One of the biggest frustrations of having a backyard garden fish pond is not knowing what to do when the water becomes mucky, green and gross!
Don’t worry, there is a way you can naturally clear the pond water without using harmful chemicals. Keeping pond water clear the natural way is easy, and you’ll be able to enjoy your pond again in no time.
Help! What’s Growing In My Small Garden Pond?
Last summer my little garden pond was overcome with a mossy, weedy growth. The pond water looked green, cloudy and disgusting.
After doing some research about small pond care, I discovered that the green stuff growing in my pond was string algae. Yuck!
Turns out that string algae growth in ponds is a super common problem.
Why You Want To Get Rid Of Pond Algae ASAP
Not only does it look terrible, but algae growth in ponds is bad because it can take over a small pond quickly. When left to grow, pond water algae can eventually starve the fish and plants of necessary oxygen and nutrients.
I was pretty nervous when I first started reading about algae in pond water.
Mainly I was worried that I’d have to use expensive chemicals for clearing my pond water. Plus, those chemicals might kill my fish and plants… or, even worse, it could cause me to have to start over from scratch with my pond.
Needless to say I was thrilled when I discovered that there is a home remedy for pond algae control. As it turns out, clearing out garden pond algae naturally, and keeping pond water clear is easy. Whew!
How To Clear Pond Water Naturally
It sounds strange, but the answer to natural pond algae control is barley straw.
Not only is barley straw a natural pond algae killer, but it won’t harm your fish or plants – and it’s cheap to buy too.
In fact, I’ve read that barley straw is a more effective pond algae remover, and it works better to clear pond water than expensive chemicals.
Win, win, win, win!

Fish swimming in clear pond water
You can find technical explanations on the internet for why barley straw naturally clears pond water.
But basically, as the barley straw decomposes it releases something similar to hydrogen peroxide (H2O2) which will eventually kill pond algae.
Whatever the technical reason is, it works great for treating pond algae!
Natural Pond Algae Treatment Use Tips
You can buy barley straw for algae control in ponds at your local garden center, or on the internet. You can also buy barley straw in liquid form, or you can get barley straw pellets.
When I bought my barley straw, it came packed in small bales that were much too large for my pond (pictured above).
The package says that each bale of barley straw will treat 1000 gallons of water.
My small garden pond holds only 90 gallons of water. So I made smaller bundles out of the mesh packaging the barley straw bales came in when I bought them.
I used twine string to tie the opening in the mesh closed, and also to hang the bundle from my pond waterfall.
It’s best to put your barley straw bundle in the pond near a fountain or waterfall where the water will flow through it.
Once the straw starts to decompose, the bundle will sink so it’s no longer visible on top of the water.
Keep in mind that controlling algae in ponds using barley straw will take a little longer to than it would with chemicals. It takes a few weeks for the barley straw to begin to decompose and start clearing the pond water.
So, if you want to start seeing clear water faster, there are a few steps you can take now with these easy pond maintenance tips.
Easy Tips To Clear Pond Water Faster
- Manually remove algae from fish pond: To speed up your garden pond algae control efforts, start by manually removing as much of the algae from your pond as you can.
Don’t worry this sounds harder than it is.
An inexpensive toilet brush works great for getting rid of algae in a pond. You can remove the algae by scrubbing the sides of your pond with the brush.
Ideally, you would buy a new toilet brush to use specifically for your pond; what would be more disgusting – using an old used toilet brush in your pond, or using your pond brush in your toilet!?
- Rinse your garden pond filter daily: If you have any type of pond water filter system installed, rinsing the filter daily during this time will also help to remove pond algae faster.
If your pump didn’t come with a filter, I highly recommend you get a universal pond pump filter box. It will make keeping your pond water clear (and general pond maintenance) so much easier!
Or you can make your own DIY pond pump filter box using these super simple step-by-step instructions.
- Use hydrogen peroxide (H2O2) to help clear pond water: Another thing that works great for algae control in fish ponds is hydrogen peroxide (and no, it won’t kill your fish!).
I don’t know if there’s a special formula of H2O2 per gallon of water, so I recommend doing some research for your specific pond size.
My small pond is 90 gallons, and I added a 1/2 cup of H2O2 to the water. Pour the H2O2 over the running water of a fountain or waterfall to disperse it.
Shortly after adding the H2O2 and barley straw to my pond, and following these steps to clear my pond water faster, I started to see results.
In no time, my pond water was crystal clear, and it stayed that way all summer.

Pond Water Is Naturally Clear
How To Keep Pond Water Clear Naturally
Now I put a new barley straw bundle in both of my little garden fish ponds in the spring as part of my regular small pond maintenance schedule. Since doing this, I’ve been able to avoid algae growth in my ponds, and keep the water clear. One small barley straw bundle lasts all summer.
Another thing I make sure to do as part of my regular fish pond maintenance tasks is to remove the leaves and other debris from my pond. My pond skimmer net makes this task super easy! Regular pond maintenance is very important to ensure the water stays clear! Learn how to clean your pond with my easy DIY fish pond cleaning instructions.
Related Post: How To Winterize A Pond Step-By-Step
If you’re having problems keeping your pond clear, and algae growth is not the issue (or if you’re not sure what the problem is), then I recommend testing the water.
You can get an inexpensive pond water test kit that is specifically made for testing pond water, and that will help you figure out exactly what type of treatment the water needs.
I love my garden ponds again now that I the water is clean. It’s nice to be able to watch my fish swimming around in the crystal clear pond water, feeding on worms and other bugs that fall into the pond.
Plus my ponds are constantly filled with frogs and salamanders too – a wonderful sign of a healthy pond!

Frogs are a sign of a healthy pond
Recommended Reading:
- Backyard Water Gardens
- The Water Gardener’s Bible
- Water Garden Idea Book
- Encyclopedia of Water Garden Plants
Products I Recommend
Share your tips for keeping pond water clear naturally, and backyard pond algae control in the comments below.
Tootsie says
I wonder if this will work in my fountain? I think I might try it. My fountain holds about 10 gallons of water….and it gets just gross after a while. thanks for the tips! I am a new follower!!! been stalking you on the facebook for a while…but now am on GFC too!
donna says
hi would anyone recommend to get rid of green fish pond water have tryed lots of things
but cant get rid of it thanks
Amy Andrychowicz says
The full instructions for how to get rid of green fish pond water are in the blog post above. 🙂
Don says
I suggest iris pseudacorus zip tied on a milk crate and placed at water level. It is aggressive, and you might need 3-6 of these crates depending on size of pond and movement of water. Mine are in a bog filter and upper pond, but I am starting a 650 gallon pond with no flow/pump, with them right in the pond.
Amy - Get Busy Gardening says
Hi Tootsie! Thanks for becoming a new follower. I enjoy your blog too! Funny you should ask about the fountain. We have moss growth on our fountain too and I just poured some H2O2 in there to see if it would work. I don't see why it wouldn't. What the heck, it won't hurt to give it a try! Hydrogen peroxide is cheap to buy.
Good luck!
Amy
ester says
Hello, im curious om the peroxide… my pond is about 390 gal round galvanized stock tank …. how much would i pour in the thanl??? i have about 7 baby gold fish and 5 lg fish . koi. gold fancy tail gold fish ….would it hurt them…. i have one plant in there its a lilly pad lots of green floating algae on the top,i have to skimp off the alea everyday just so i can see my fish….
thanks again..
Amy Andrychowicz says
Humm… I’m not an expert on how much peroxide you should add per gallon of water. I use a 1/2 cup in my 90 gallon pond to help get a head start on killing the algae cause barley straw takes a few weeks to start working. So, you can do the math based on what I’ve used. Make sure to disperse it as evenly as you can throughout the water – don’t just pour it all in one spot. I too have goldfish and plants in my pond, and have never lost any of them because I used peroxide. (I wouldn’t recommend pouring it directly on the fish though.)
Diane Smith says
I never tried peroxide but did add small amt of Chlorox bleach to a 10 ft pond. Killed the goldfish, Killed the mosquito fish. Never again.
I never had a floating device for the barley I tried. Put it into a nylon stocking and never such much improvement. Am ready to find a float and try again.
Any recycle ideas for the float?
Amy Andrychowicz says
Yes, I definitely would NOT recommend using bleach. That will kill the fish for sure, and might also kill the plants in the pond. Sorry for your loss. 🙁 I’m not sure what you’re asking about a “float”, sorry. I tie my barley straw bundle to the fountain in my front pond, and right at the bottom of my waterfall in my backyard garden pond. The barley straw bundle needs to be next to the running water source in order for it to work. The bundle will float on it’s own, and once it starts to break down, it will eventually sink. I can get it out easily buy just pulling it out by the string so it won’t sink to the bottom. The larger the pond, the more barley straw you need (it has instructions on the package).
Gazza says
Hi Amy i am in thailand and my pond is 7,000 litres. It is in direct sunlight for about 4 and a half hours per day. I clean it out and the green comes back after 4 or 5 days. Will the peroxide help this?
Amy Andrychowicz says
Have you tried the barley straw yet? With a pond that size, hydrogen peroxide isn’t a good option because you would need a LOT of it.
Zak says
Hi am in South Africa I use a product called Aquazyme
I really works well for algae control
Hopefully you have a pump and a U V light system set up on the water return
Pete says
Hi, my pond is 400,000 litres. I have a full-sized barley bale float in it. I have a weightlifting weight attached a metre below it so it floats around the middle. It has a long rope to the bank to allow for me adjusting it’s position in the wind. No algae. Works perfectly and sinks level with the surface after a few months. Is replaced annually.
Lydia Harris says
I have a 100 gal pond and bought algae chemical from Walmart and it killed 10 of my big goldfish😢 n all my live plants so starting from scratch, so how often do I put 1/2c of hydrogen peroxide in my pond from now on to keep it clean along with a sm bundle of barly straw
Amy Andrychowicz says
Oh no, I’m sorry to hear about the loss of your fish and plants! That’s a huge bummer!! Pond chemicals always scare me. Once the barley straw starts to decompose, you won’t need to use the peroxide anymore. It takes a few weeks for the barley straw to start to break down. It will start to sink once it’s breaking down. I add the peroxide to my pond water once or twice before the straw starts breaking down. Here’s a post I wrote about cleaning fish pond water, which may also help you keep the water clean through the summer.
Alan says
I had the same problem with the floating algae. until i got me a floating skimmer on amazon, i also drained about half the water out and refilled it, i also tinted the water with (pond tint) because my pond is in full sun all day. untill the banana tree’s grow out that is.
PlantPostings says
Cool! What a great lesson! If I ever get around to building a pond, I'll try to remember this. I love ponds. It will be fun to see more posts about yours!
Amy - Get Busy Gardening says
Hi PlantPostings – Glad you enjoyed the post. Having a pond is pretty easy once you understand the basics of keeping a healthy balance so it won't become a maintenance nightmare. I have a few more posts planned for this summer about my ponds, so stay tuned! 🙂
Amy
Alexis says
Hi There,
I just ran into this problem with my fish pond. I noticed that homedepot sells Barley Pond Clarifier, do u think I can use this for our pond? If so, I have goldfish in the pond now. Should I put this chemical in the pond while the fishes are in there? Would it harm the fish? Please advice. Thanks.
Amy Andrychowicz says
The label should say if it’s safe for use in a pond and if it’s safe for fish. If it’s the Barley Straw extract, then it should be natural and safe to use – but make sure to read the label.
Barbra says
I have used the liquid barley and it is safe. Also see for dogs that drink from your pond.
RandomGardener says
Thanks for the information! When we have a pond(hopefully soon), it'll be good to know about these things! I never even thought about the problems with a pond!
Amy - Get Busy Gardening says
Hi RandomGardener – Funny! I never thought about problems with a pond before I put my first one in. Why would you ever worry about stuff like that? 🙂 I put in the small 90 gallon one as a test one to make sure I could handle it before I went larger (I didn't really go much larger as it turns out). But a pond sounds much scarier than it is, it's pretty easy to maintain once you get the
Anonymous says
Amy;
We are really impressed with your page, and now have new direction to clear the water in our problematic 250 gallon pond. I will relay our progress and success as it happens, along with any new information we come across in hopes to help you or your followers. Thanks, Tomm
Amy Andrychowicz says
Hi Tomm!
Thanks, glad you found my blog. Hope this method will help you keep your pond clear. I would love to hear about your progress, and how it goes for you. Good luck!
Amy
Brenda says
Will hydrogen peroxide hurt the fish?
Amy Andrychowicz says
It might if you pour it directly on them. But, if you use the recommended amount and pour it over your fountain or waterfall to disburse it, it won’t hurt the fish. I’ve been doing this for a few years and have never lost any fish.
Anonymous says
I bought property and had an overgrown pondan area. We got excited my birthday came an my nephew cleaned ut pretty good then added fish. Onjy gad it for three weeks.already see grreen hairy stuff ansludge too.with aiiwe have to do I need some easy steps I have no pump just running water.please help me out.don't think its 500 gallons but Huerta guessing.I sure want to enjoy it.help needed!
Amy Andrychowicz says
I would start by taking a brush and cleaning out some of the algae (like I describe above). Next, I would add hydrogen peroxide (I use 1/2 cup in my 90 gallon pond, so you can do the math for your pond). You said you don't have a pump, but do have running water so just pour the peroxide over the area where the water is running into the pond. Or you can disperse it around the pond yourself.
Peggy says
Even with it being the middle of summer we just got our pond going again about 2 weeks ago with rebuilt sides and stepping stones around side because our small boulders on side of pool kept falling in. Our water garden is in the sun from noon until sundown we are trying to get more plants and fish. only have 3 small orffs and 2 gold fish now. will get more if these do ok for a couple of weeks.
Amy Andrychowicz says
Yes, I would add barley straw and treat with peroxide now. I leave barley straw in mine year round, refreshing it every spring. It certainly won't hurt to add it this late, and it will start to break down before winter. Next spring, add new barley straw. Hope this helps.
Amy
Niki says
Sorry not sure why my words deleted? I have a pond 1 1/2 metres deep, can I ask why you take out the barley straw and not let it decompose fully in the bottom when it sinks?
Amy Andrychowicz says
My garden pond is really small, so that’s why I always remove the barley straw every spring to add a new bundle. But I guess you could just leave it in a larger pond. Just make sure you use a material that will also decompose when you make your bundle.
Pranshu Goel says
Which brand Hydrogen Peroxide are you using ? and what is the percentage Food Grade or Commercial – 3% or 35%
Amy Andrychowicz says
I just buy the generic brand at Target. It's 3%. I find it in the first aid section.
Josie says
35% will burn skin and kill anything it touches! Use the 3%:)
Camille Hatcher says
Thank you, ever so much for this post! Couldn’t have been more timely . . . we bought our house in May and with it came a large koi pond (guessing about 500-600 gallon). It needs cleaning desperately and until reading your article I had not a clue how to go about it.
Amy Andrychowicz says
Wow, that sounds awesome Camille! I’m glad I can help. Enjoy your new pond!
Amy
Susan Bundlie says
Our pond is about 20 acres. A few years ago I read an article about making an island out of barley straw and planting things on the top of it to control algae. For a water area this large, that can get to be very expensive. I’ll have to organize all the neighbors who live on the water and see if they will all chip in. Maybe next year.
Amy Andrychowicz says
Wow, that sounds like it would be really cool. Time for a fundraiser. 🙂
Heather says
We have a 4000-5000 gallon natural pond in our yard with several koi and comets. The string algae is always a problem in the spring. We’ve treated with barley extract a couple times but it didn’t seem to having long lasting effects and ended up adding the chemicals to control the out of control algae. We added several water plants which seemed to help some. Now that I’ve read your article, I’ll try the barley bale from my local garden center and the peroxide as well…it’ll be a lot more than a 1/2 cup 🙂 Thanks for the ideas!
Amy Andrychowicz says
Haha, yes you’ll definitely need more than 1/2 a cup for your huge pond! I hope the barley straw will do the trick for you, good luck!
Deanna Oster says
i was wondering if timothy hay would work the same way. i have many goldfish in my 90 gallon pond. would the peroxide hurt the fish?
Amy Andrychowicz says
I was told that only barley straw works in this way. The peroxide doesn’t harm the fish, I use it in my ponds all the time (I have goldfish too).
Greg Beck says
How often can you add peroxide?
Amy Andrychowicz says
I would say once a week, or once every other week until you start to see the string algae dying back. But, if you have a ton of algae growth in your pond, try to remove as much as you can with a toilet brush (or other brush) before treating your pond with hydrogen peroxide. Otherwise, it can be really hard to clean the pond once the algae starts dying.
Jen says
Hi Amy! I am excited to try this!! Gonna purchase some barley straw today! I was using chemicals, and wanted to find a natural way of clearing my pond of guck! Thank you for this post!!! Aloha, Jen
Amy Andrychowicz says
Great, glad to hear it! Hope it works as well for you as it has for me.
Dani says
I am thinking of doing a couple of recycled tire ponds in my backyard but I have dogs and I live in MN so breeding bloodsucking mosquitoes is a problem. Do you have any recommendations? I don’t plan to do fish as they wouldn’t survive the MN winter in such a shallow area. Will I need something to keep the water moving? I’d use chlorine but it’s not safe for the dogs. Any suggestions would be great
Amy Andrychowicz says
I am also in MN and I use a stock tank heater to keep the water in my ponds from freezing to the bottom. Mine are in the ground though, so if yours is going to be above ground, the stock tank heater probably won’t keep it from freezing. I recommend buying inexpensive goldfish. They will eat all the mosquito larvae and are cheap enough that if they don’t survive the winter, you can replace them every year (they’re like $.10 or $.25 cents a piece at the pet store). But, the goldfish will hibernate and survive the winter as long as the water doesn’t freeze solid. I’ve had them survive 5+ years in my small garden pond.
Shirley Mc kinney says
I buy most of my gold fish at the bait store for my pond. They seem to be hardier than those sold at the pet stores. You can find some rather pretty ones there also, plus cheaper!
Brenda says
I was wondering if hydrogen peroxide will hurt koi or goldfish in my pond?
Thanks
Amy Andrychowicz says
No, it won’t hurt them as long as you stick to the recommended amount. I have goldfish in my ponds.
laurie clark says
hi
we have a pond which has 2000 gallons of water. We r having trouble with the algae it’s like a fine dust floating around n it will just brush of rocks n sticks to plants will hydrogen peroxide help this n do u kn what kind of agae it is
thanks
laurie
Amy Andrychowicz says
Sorry, I don’t know what type of algae it is, but the barley straw/peroxide trick should work the same for any type of pond algae. Make sure to skim the algae regularly while you’re treating the pond, that will get rid of it much faster. Good luck!
Andrea Tobar says
can I Use wheat?
Amy Andrychowicz says
No, it has to be barley straw.
Jay says
When you brush the algae off though it just goes straight into the water, which I doubt is good for the fish? Having this problem myself when cleaning my fountain, all the muck goes straight in. Any ideas?
Amy Andrychowicz says
True, but that’s why you have to rinse the filter on a regular basis. That will help clear out the algae.
Victoria J. Maniquis says
I have a 10ft. Height waterfall leading to my koi pond and ends up in a gazebo. I live in a tropical country. I don’t think we have barley straws here. Can you suggest anything else?
Hope you can help. Thanks.
Amy Andrychowicz says
You can buy barley straw online. I’m not sure if you can shop on Amazon from where you live, but here’s the barley straw that I buy… Barley Straw
I also mentioned a few products you could try in the post above, here’s a list of a few things I’ve also used…
(FYI, these are affiliate links)
If you can’t order this stuff online, then I recommend going to your local garden center and ask if they carry any of these products, or if they know where you can find them.
Candy says
Using this method, would the water be safe for my dogs to drink?
Amy Andrychowicz says
Well, I don’t have dogs so I’m not sure how “safe” pond water is for them to drink. 😉 But you can feel safe knowing that you’re not putting any yucky chemicals in the water that could be harmful to your dogs if they drink the water.
Julie says
We moved last year to a house with a tiny pond with a big algae problem. I have just been removing it manually so I’m happy to give this a try. thanks.
BTW cleaning the pond with a toilet brush is way more gross that cleaning the toilet with the pond brush in my opinion anyway!
Amy Andrychowicz says
Awesome, hope it works well for you.
LOL, I agree! Love it.
Cindy says
I hope to some day get to have a little pond in a backyard somewhere(we’re in a duplex right now). This is good info to know. I’ll also pass it along to my mom whose pond is generally getting a bit of algae in it by the end of summertime. Thanks so much for the tips!
Amy Andrychowicz says
Awesome, thanks! You’re welcome. 🙂
Judy says
I have a 250gal pond with Koi in it. I’m constantly having to change the filter. We’d like to do away with the filter entirely and only use an aerator. We want to cut down on the maintenance and use only barley straw and lava rocks. Any suggestions and would this work?
Amy Andrychowicz says
Sounds like a great idea. I would definitely talk to someone at your local nursery (where they sell backyard pond equipment) and get their advice. Sorry, but I don’t have experience doing that. 🙂
Simone says
I have a house that came with a pond and had no idea what to do with it. This info is right on time! Thanks!
Amy Andrychowicz says
Perfect! Thanks for stopping by!
booboo says
I have just brought barley straw off of the internet for the pond, to eliminate green/algae;
it is already in nets; does it need anything added to it or treating with anything first? Do I just put it in the pond and leave it? Is it harmless to fish and pond life?
Amy Andrychowicz says
You just need to put it in the pond and leave it. It will eventually sink. No, it’s not harmful, it’s completely natural and safe to use.
Tammy in NY says
Hello I just recently put in a small pond (its just the tub that you buy with the kit – I bought used) I scrubbed it before putting in the ground and doing my landscaping. I do plan on buying the pump to do a waterfall but for now it’s just there. I bought some feeder goldfish, a albino frog and 2 fantail gold fish but unfortunately we cant see them cuz the water is cloudy but way too soon for algea. Would the peroxide work?
Amy Andrychowicz says
You can definitely give it a try, it should help. But it would work best of you put a pump in there (even it it’s just a bubbler) to aerate the water and help to circulate the peroxide.
Chris Pendleton says
Hey Amy great story I have a natural alternative that won’t cost a dime
I live in the Ohio Valley, New Albany, IN five mins across the Ohio River from downtown Louisville, KY. Anyway, the sun is strong here and algae is problem if your pond is not covered with 60% of the top in shade whether you use floating plants or some sort of coverage to prevent the algae blooms. I open and close peoples ponds and keep them clean as a side job. After doing some research I learned you can take simple branches of weeping willow depending on the size of your pond I d say about one branch for every 10 gallons of water. The best way to remove the branch fromthe tree is by making a clean cut with a knife or razor blade and this will not harm the tree it will regroup the branch. By making a clean cut with a sharp object it does not disturb the water vein in the branch like it would if you used shears or scissors. That would pinch and close off the water vein. Place your cut end of the branches into your pond, bird bath, fountain, etc. Around 5-6 days you will notice roots forming from the cut ends and those branches will now start taking in nutrients ffrom the water and starve and deplete the algae from getting them which in turn kills the algae and now you have starts of new willow trees that you can plant in the ground. You can leave the branches in the water for as long as you like. But the best way to keep the algae out long term is to have 60 % of your water feature shaded either by floating plants, a roof, or by using pond dye. Hope your followers try this inexpensive treatment and raise new willow trees from it. Enjoy your day evryone! Chris Pendleton-New Albany, IN facebook.com/stylinstud
Amy Andrychowicz says
Wow, that is so awesome! I love this idea and I’m totally going to give it a try. Thanks so much for sharing Chris!
Diane Smith says
Now all I have to do is search for a willow. I will try it. It makes sense to me. Because of willows’ penchant for growing into plumbing problems, people don’t use them much anymore for landscaping. I grew up having tea parties and other pretend parties under one huge shady willow.
One tip from me: If you have ailing trees, roses and other shrubs, planting willow slips around them usually cures them. It has medicinal properties for plants.
Amy Andrychowicz says
Interesting, thanks for the tip!
Ryan says
FYI when the barley straw decomposes it actually produces H2O2, so skip the middle man and go straight to the H2O2. For small ponds, the 3% stuff is fine. For larger ponds, it’s cheaper to get the 27% (often sold as chlorine-free pool shock). When H2O2 breaks down, it forms H2O (water) and O2 (Oxygen), so it is safe once it breaks down. The key is to make sure it breaks down! This is more of a factor of how much organics/algae you have as opposed to total volume. If your water is brown, with a lot of leaves and algae, the H2O2 will break down quickly. If your water is mostly clear, start with minimal doses, and repeat every couple days if needed.
Some reading from people way smarter than I!
Amy Andrychowicz says
Thanks for adding your tips!
Kelly & Randy O'Reilly says
Our pond is 12,000 gallons, will the pool shock be safe for our plants and fish?
Marsha Bailey says
I used charcoal in mine. After it settles it works great.
Amy Andrychowicz says
Cool! Is it a charcoal filter, or do you just drop bits of charcoal in there?
Molly Ackert says
We just bought a house on a shortsale..It has two ponds. One in a walled in area(which has an electric filter which clearly has not been turned on in years) and the other is about 50 feet by 40 feet. Also is in sad state. I will immediately get the barley, a skimmer net, H2O2, and some goldfish. There are cat tails growing along the bank in areas. Do we need an aerator? Your article is superb. Thanks so much
Amy Andrychowicz says
I would recommend you test the water in your ponds before you add fish. You might have some work to do to get the water clean enough for them to survive. Here are some test strips that you can use… Pond Test Strips Goldfish are cheap, but it’s not worth the effort of adding them to the ponds if they’ll only die shortly after. 😉 I would start with that, and then go from there. Once you get the water healthy and ready for fish, then you can look into buying an aerator.
Helga says
Hi Amy
I don’t know if you still read these emails.
I live in Australia on the Sunshine Coast. This area is tropical but has cool winters.
We just put a tyre pond in. I have 4 gold fish at the moment, some water plants and stones at the bottom of the pond. I have a small solar water fountain which only works during the day. This will be made into a waterfall going from one pond to the next- we used two tyres. My goldfish are very happy but I can feel the sides of the pond starting to get a bit slimy. I will definitely try the hydrogen peroxide trick and get some barley straw. What a wonderful idea.
I will save your site onto my desktop.
I will also be looking at buying some fish that eat mosquito larvae which is also a problem here in Summer. If I get some more water plants will they also help to keep the pond healthy?
Kind regards
Amy Andrychowicz says
Sounds wonderful! Goldfish eat mosquito larvae, so you should be fine there. Yes, adding a few plants will also help to keep the pond healthy. I have hardy water lilies growing in mine, they’re beautiful!
Sara says
There are fish that eat algea which is great but they cannot tolerate cold weather. You can buy them in most stores that sell fish. Snails eat algea too. There are some very large snails that can be bought for outside ponds. They are difficult to find though.
Amy Andrychowicz says
Thanks Sara. Great tips! I have thought about getting one of those bottom feeder fish that eat algae, but I would feel terrible when it died over the winter. I think it would be really hard to find it in the pond to take it out in the fall. LOL!
Dave says
Hi Amy,
Great thread. I have a 250 gallon pond. My questions is: can one put too much barley in the water? I’m noticing most commercially packed barley bails are for 500-1000 gallons. Do I need to reduce the size or can I put a barley pack designed for a 1000 gallon pond into my 250 gallon pond? Thanks in advance!
Amy Andrychowicz says
I reduced the size of the straw bales for my small backyard garden pond (as you can see in the photos above). I don’t think you can add too much barley straw… but I thought it would be wasteful (and ugly) to use the huge straw bale in my tiny pond. Breaking it apart means I get more uses out of one bale.
Marcela says
Hi Amy, We are building a natural pond and need some advise. We live in South America 2.800 meters over sea level rains a lot but the sun is strong too year round? Can you please suggest plants to buy and any other tip will be welcome.
Best regards
Amy Andrychowicz says
I grow water lilies in my pond. They are very cold hardy, and they flower every year. I’m not sure what you comparable growing zone would be in, so it’s tough to recommend plants that will grow well for you. But some common pond plants are water lilies, cattails, papyrus, water irises, taro, water hyacinth, canna lilies and umbrella plant. There are lots of water plants to choose from though, some are hardy and some are tropical (not cold hardy). Also, check your local garden center to see what they recommend.
Dave says
Thanks!
Buggins says
We have tried any amount of barley straw in our smallish pond and found it absolutely useless!
Maybe there’s a special kind of barley straw and you need to know the codes/passwords/special handshakes to obtain a supply, but the stuff we bought from our garden centre changed nothinh.
The toilet brush tip is a good one though. I have recently used an industrial style wire brush with remarkable results..
Most of the blanket weed has now gone, but unfortunately the goldfish have developed rust spots..
Amy Andrychowicz says
I’m not sure what kind you bought, but this is the type that I buy… barley straw. Keep in mind that it takes a while to start working, so you won’t see any results right away. The barley straw won’t work until it starts to break down, and could take a month or so to start working.
Tina Novotny says
Hi Amy,
What kind of waterfall pump do you recommend for a small pond and where can I find one? I don’t want to buy an expensive one.
Thanks,
Tina
Amy Andrychowicz says
It depends on the size of your pond, and the height of your waterfall (if you have one). This is the pump I have in my small pond (which is about 120 gallons). The waterfall is about 3-4 feet from the bottom of the pond, so this one is more than adequate, and works great for me! It pumps 330 gallons per hour, and works great for waterfalls under 7 feet tall.
Tina Novotny says
Hi,
Would the following be a good one that includes everything?
https://www.amazon.com/dp/B0068MW50M
Thanks,
Tina
Amy Andrychowicz says
That one would work great for a small pond, and comes with a fountain attachment rather than a waterfall. But, if you have a waterfall, you can still use it, you just have put a tube attachment on there instead of the fountain attachment.
Brandon says
This is awesome! I have to try both ideas thank you for sharing 🙂
Amy Andrychowicz says
You’re welcome!
Sarah Kaser says
How often do you treat your pond with peroxide?
Amy Andrychowicz says
I only use the peroxide as needed before the barley straw starts to decompose and work it’s magic. I probably use it about once a week or so.
Buggins says
The wife and I spent FIVE hours clearing out our small fishpond. There was four inches of sediment on the bottom (which stank!). Took out the irises, took out the lily pads..
We cleaned it all out, put pebbles on the bottom, filled it up and re-introduced the five goldfish.
First three days lovely and clear, and now beginning to get a very slight haze in the water..
We don’t over feed the fish, we only have two plants in there
My guess is it’s a combination of rainborne/windborne dust plus fish poo.
I am going to try rigging up two solar powered pumps to draw the water through a home made filter and re-cycle clean water back in.
Or I might fill the darn thing in!
Amy Andrychowicz says
Yes, all of that muck is caused by fish waste, and also bugs, leaves and other debris that falls into the pond daily. It’s a good idea to get into the habit of skimming the debris off the top of your pond regularly. This is especially important in the fall as the leaves are dropping. Adding a filter will help a ton, along with the barley straw treatments I’ve described above. Good luck!
Leslie says
I am planning on putting in a small pond on my patio garden. I really like the idea of using a natural algae remedy. I wonder, do I need to wait until there’s algae in the pond to use the barley straw, or could I put the barley straw in the pond from the beginning to keep the pond clean? Does it work as the algae is forming (I’m assuming, since I live in a hot climate, that there will be algae very quickly?) I’ve been living in rentals for 10 years and I’m excited to have my own space to make a garden. Thank you for your advice.
Amy Andrychowicz says
You can put the barley straw in from the beginning, it won’t hurt anything. Have fun with your new garden, how exciting!!
John Winlow says
We have emptied our small pond of sludge etc, cleaned it out wire brushed the blanket weed off the sides, put largish pebbles on the bottom and installed a small pump. I made a simple filter out of a plastic swingbin, using aquatic grade fine foam and an old fine weave cotton cloth folded up to catch the tiny particles.
This is working great for us. No more murky water, just filtered re-cycled pond water..
I put the pebbles in so that every now and then I can use a water hose to stir up the junk on the bottom and let the pump filter it out.
Hope this helps.
Liberty says
Can you use this in stock ponds? i have a pond that is cover with green stuff. we don’t have livestock using it.
Amy Andrychowicz says
I don’t see why not, since it’s non-toxic. But, I’ve never read anything about it, so you might want to do a bit of research about that first.
Franz CRIEGO says
I have a unique problem. I have planted plants in the bottom of my 6ft pond. THe water turns over every 1.5 to 2 hours and I use a UV clarifier with a bead filter. The koi have shredded my plants and I am unable to produce “clear” water due to the debri left behind. HOW or what do I do to “clear” my water?
Amy Andrychowicz says
If the plants are still in there, and the koi are constantly shredding them, I don’t think you’ll ever be able to clear it. I would remove the plants, and then use a filter that will pull the debris out of the water, and keep cleaning it. Also, use a net to fish out as much of the debris as you can to help speed it up.
Shelia B Glenn says
We just finished our pond. It’s to cold here to run the waterfall. Putting a barley in will that still work? We have put a screen over to keep leaves out.
Amy Andrychowicz says
I would wait until spring to add the barley straw.
hans says
i sort of wonder if barley straw would work – and for how long – with a pond in Mexico’s ‘hot-zone’ La Huasteca , with 35-45 o Celsius and 80-90 % air moisture ,,,, and of course no barley straw around …. ??
Any answers ?!?
Amy Andrychowicz says
I’m sorry but I don’t understand what your question is. Please rephrase. 🙂
Julia says
My pond holds about 500 gallons. It has an upper tank which overflows down a series of waterfalls. It started getting very green and murky so I built a small campfire, added a large log to the fire and let it burn until it was a large chunk of charcoal. Then I put out the fire and let it coool down completely. I tossed it into the upper tank. When I checked it the next day the water was crystal clear and I never saw any green murkiness in my pond again. Fish and plants all beautifully healthy.
Amy Andrychowicz says
Wow, that’s awesome! Thanks for sharing the tip, I knew that charcoal helped to keep water clean, but I had no idea you could make your own, LOL! I might just have to give that a try next summer.
wendy says
The Barley Bags did not keep my pond clean, they ended up getting algae on them also, and turned green… any other suggestions for natural way?
Amy Andrychowicz says
Are you certain you used barley straw, other types of straw will not work? If so, did you use enough barley straw for the size of your pond? I have included a few other suggestions for natural ways to clear your pond under the “Natural Pond Algae Treatment Use Tips” section above.
carole says
What strenth Peroxide is used 10%, 20% 30%…?
Amy Andrychowicz says
I use 3% for my small garden pond, but read through the other comments here because others have chimed in with their experiences too.
Theodore c Young says
Barley is good in controlling string algae. As to the pea algae or algae that turns rocks green I have not found a solution for that.
Bobbie says
I just had a pond built. No fish yet. but it gets hot and humid here in south Texas. Should I start caring for algae now? I Can get barley straw at my gardenc enter. I’ve been told to wait at least a month before introducing fish.
Amy Andrychowicz says
How fun, congrats on your new pond!! Yes, you can definitely put the barley straw in there now to get a jump on any algae growth. You could check at your local garden center, most of them around here (I’m in MN) do carry barley straw. I’m not sure why you have to wait a month to introduce fish. You should only need to wait 24 hours for the chlorine to evaporate, that’s what I do. But I have goldfish in mine, so maybe koi or other types of fish are different, if you’re getting something besides goldfish.
Shirley Sauls says
Hi Amy, I have really enjoyed reading your site and all the comments. I would like to ask if you have heard any thing about helping clear your pond with building a waterfall that runs down like a small little rock stream going to the pond.i was told that is the natural way to keep your pond clean. My pond has algae terrible ! I can’t see my fish unless the are swimming at the top. Makes me so sad.🙁 I am going to try the barley straw and peroxide also. Please let me know if you have heard of the small rock stream for cleaning a pond. Thank you so much !
Shirley
Amy Andrychowicz says
I haven’t heard of that. I have a waterfall next to my pond. The water is pumped from the bottom of the pond to the top of the waterfall. It trickles down the rocks of the waterfall, and cycles back into the pond. It definitely doesn’t stop the algae growth just by doing that though. Putting a filter on the pump definitely helps, but it’s the barley straw that kills the algae.
Chris says
Test your pond water if you haven’t already. Mine was green and stayed green even after trying to add algaecide and bacterial boosters and barley straw ($300 worth of products) over the course of 6 weeks. Finally tested the water and found that the KH/GH was low and ph was high. Added about $6 worth of baking soda to raise the KH/GH and regulate PH. The water cleared up in a week!
Theodore c Young says
Barley straw only kills the string algae. In order to deter the other types of algae make sure 50% of your pond is covered with plants. Too much sun promotes the growth.
Just sayin
Amy Andrychowicz says
Using pond plants to shade the water from the sun is a great idea, thanks for the tip!
Paulette says
Hi I read that you have frogs in your pond. My pond is also about 90 gallons so my goldfish are relatively small maybe 4”. I’ve always loved the idea of having frogs but afraid they would eat the small fish. How big are your fish? Do you have a problem with frogs eating them? Thanks
Amy Andrychowicz says
I also just have goldfish in my pond, and have never had problems with frogs eating them. Since my pond is outside, I would never be able to keep the frogs out anyway, LOL!
Gay says
Do you have a problem with raccoons or water snakes invading your pond?
Amy Andrychowicz says
I haven’t had any problems with critters invading my pond. We do have lots of frogs and I’ve also seen salamanders in the pond, but nothing invading it (well, unless you call 15 frogs having a party in there on a hot day an invasion, LOL!). I’m sure that wildlife like raccoons drink from my pond regularly (I’ve seen lots of birds and even squirrels taking a drink), but the raccoons have never done any damage or eaten my fish (that I know of anyway). Knock on wood!
Kristy says
Our goldfish got sucked into the filter/ pump area. Any suggests for this?
Amy Andrychowicz says
Oh no! So sorry to hear about your fish! I’m not sure what type of filter or pump you’re using, but I’ve never had that happen to my fish. I would recommend getting a universal filter box if that would work with your pump. That’s what I use, and my fish have never been sucked up.
Cindy says
We use panty hose. WTer filters through but fish and frogs do not. Pool and big name hardware stores with garden centers sell them specifically for the pump and filter. They allow the water to flow through trapping debris and thicker algae.
Sharin says
Can u put devil vine n ur garden pond? Or will it take to much oxygen out of my water. Don’t want to kill my goldfish or koso fish
Amy Andrychowicz says
Plants actually help to add oxygen to the water, they don’t take oxygen out of the water. I’ve never grown devil vine (I think you’re talking about pothos?) in my pond before, but I don’t see why you couldn’t give it a try. I have water lilies in mine, and overwinter them in there with the fish.
Keith Tuck says
Another good way of keeping algae down is to have an Ultra Violet lamp in your filter system. I used to have a filter box with built in ultra violet lamp when I had a small pond and the water stayed crystal clear.
Amy Andrychowicz says
Wow, cool. I’ve never heard of a pond filter with an ultra violet lamp. Thanks for the added tip.
Dale Burleson says
I live in Thailand and do not have access to Barley straw. I used rice straw and it worked just as good.
Step 1.
Soak a bundle of rice straw for 3 days in water. Drain after 3 days.
Step 2.
Wrap rice straw in netting.
Step 3.
Place straw in flowing water and leave it.
Should start seeing results in about 2 to 4 weeks.
After 3 weeks the alge in my pond started to disappear and pond water is now clear and alge is nearly gone.
Amy Andrychowicz says
Great, thanks for sharing your tips and experience for using rice straw instead of barley straw to clear your pond water!
Shirley McKinney says
My pond holds approx. 1200 gallons of water. I do not have the green stuff yet this year but the water is dirty looking. What to do?
Amy Andrychowicz says
Here’s a detailed post about how to clean a fish pond that will give you all the info you need.
Robin says
Our pond holds 3600,00 gals of water, how much pine straw would I need for this? I have. 75 large goldfish and Koi, and about that many babies. Yes they seem happy. Lol
Amy Andrychowicz says
The barley straw that I buy says that each bale treats 1000 gallons. You may be able to find larger bales for a larger pond like yours.
James Parson says
I live in southeast Texas and have a 5 acre lake, and I desperately need someone to help. It’s overtaken by underwater growth and I don’t know what to do. If you know of someone in my area that could come & take a look I would be most grateful.
Amy Andrychowicz says
Sorry but I don’t know much about lakes. I would call your local city or state department of agriculture and talk to them about your options. Here in MN the lakes are owned by the state, so that’s where I would start.
Melissa Johnson says
I know this is off the subject, but I am planning a pond for my ducks and this is all wonderful advice. Does anyone know if i can put koi fish in the pond with my ducks?
Amy Andrychowicz says
Sure, I don’t see any problem with putting koi in a duck pond.
Bill says
I have two ponds, the one in the sun is a constant cloudy algae problem, but the one in the shade is always clear as drinking water, without any additives, filtration etc. Pick the location in the shade to rid yourself of all those problems, or shade it or move it if possible.
Amy Andrychowicz says
Great tip for people looking for the best location to build a new pond. Though I agree that a pond in the sun will likely have more problems with algae growth, moving it to the shade won’t necessarily solve that issue. My pond in the front is in full shade, and I still have to fight algae in there.