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 garden pond algae, I discovered that the green stuff growing in my pond was string algae. Yuck!
Turns out that string algae growth in garden ponds is a common problem. Not only does it look terrible, algae buildup in a garden pond is bad because it can take over a small pond quickly, and eventually starve the fish and plants of oxygen and nutrients.
I was nervous when first started reading about algae growth in small garden ponds. I was worried that I would have to use a chemical for clearing my pond water, and that the chemicals might kill my fish and plants… and even worse, I would have to start over from scratch with my pond. Needless to say I was thrilled when I discovered that there is a natural solution to keeping pond water clear and getting rid of algae in garden ponds.
How to Keep Pond Clear Naturally
It sounds strange, but the answer to keeping pond water clear the natural way is barley straw. Not only is barley straw a natural solution for clearing out garden pond water, it won’t harm your fish or plants – and it’s cheap to buy. In fact, I’ve read that barley straw works better to clear pond water than expensive chemicals do. Win, win, win, win!
You can find technical explanations for why barley straw works to clear pond water on the internet. But basically, as the barley straw decomposes it releases something similar to hydrogen peroxide (H2O2) which will eventually choke out the algae. Whatever the technical reason is, it works great!
You can buy barley straw 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 a smaller bundles out of the mesh packaging the barley straw bales came in when I bought them. I used string to tie the opening in the mesh closed.
It’s recommended you put your barley straw bundle in the pond near a fountain or waterfall where the water will flow through it. Once the barley straw starts to decompose, the bundle will sink so it’s no longer visible on top of the water. It takes a few weeks for the barley straw to begin to decompose and start clearing the pond water, so it will take a little longer to get results using barley straw than it would with chemicals. If you want to start seeing results faster, there are a few steps you can take now.
Steps for Clearing Pond Water Faster
- Manually remove algae in garden pond: Start by removing as much of the algae growing in your pond as you can manually. An inexpensive toilet brush works great for grabbing the string algae and scrubbing the sides of the pond. 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 garden pond filter daily: If you have a filter in your garden pond, rinsing it daily during this time will also help to remove the 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 so much easier!
- Use hydrogen peroxide to help clear pond water: To help remove the garden pond algae faster, you could add hydrogen peroxide (H2O2) to your pond water. 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 garden 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, I started to see results. In no time, my pond water was crystal clear, and it stayed that way all summer. Now I put a new barley straw bundle in both of my little garden ponds in the spring as part of my regular garden 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 is remove the leaves and other debris from my pond on a regular basis. My pond skimmer net makes this task super easy!
Related Post: Winterizing a Garden Pond
I love my garden ponds again now that the water stays clear. It’s nice to be able to watch my fish swimming around and feeding on worms and other bugs that fall into the pond. Plus my garden ponds are constantly filled with frogs and salamanders – a wonderful sign of a healthy, chemical free garden.
More DIY Gardening Projects:
- Building Sturdy Tomato Cages
- Easy Homemade Arch Trellis
- Easy DIY Garden Drip Irrigation System
- Eggshells as Organic Pest Control
- How to Build a Squash Arch
Products I Use
For more about garden ponds, click here… Garden Ponds
Do you have a garden pond? Tell me about it in the comments below.