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.
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!
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.
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.
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.
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.
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.
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.
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.
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.
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.
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!
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.
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.
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.
john h chadwick says
for blanket problemes go for clover leaf u k tried it and no prob, all clear brill, the water will turn white, with no harm to fish, but after that clean pond,
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!
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.