Keeping pond water clear the natural way is easy, and you’ll be able to enjoy your pond again in no time. In this post I will show you exactly how to get rid of pond algae and muck, without using any harsh chemicals!
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 simple way to naturally clear pond water without using toxic chemicals.
In this guide, I’ll give you all the details of how to clear pond water, and keep it clear safely, without harming your fish or plants!
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!
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 it in liquid form, or you can get the pellets.
When I bought mine, 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 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
Step 1: 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!?
Step 2: 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.
Step 3: 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.
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 properly clean your pond here.
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!
Related Post: How To Winterize A Garden Pond Step-By-Step
Keeping pond water clear and algae-free isn’t that difficult when you know how. Once you have it cleared out, it will be much easier to maintain it too – and you’ll love your garden pond again!
Recommended Reading
- Backyard Water Gardens
- The Water Gardener’s Bible
- Water Garden Idea Book
- Encyclopedia of Water Garden Plants
More Gardening Techniques
- Growing Vertically: The Ultimate Vertical Garden Guide
- Plant Propagation: A Detailed Guide For Beginners
- How To Build A Rain Garden Step-By-Step
Share your tips for keeping pond water clear naturally, and backyard pond algae control in the comments below.
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!
Helga says
Hi Amy
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!
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.
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?
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?
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!
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.
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.
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! 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. 🙂
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. 🙂
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.
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.
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…
Barley Straw liquid extract
Barley Straw Pellets
Hydrogen Peroxide
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.
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.
Andrea Tobar says
can I Use wheat?
Amy Andrychowicz says
No, it has to be barley straw.