Ponds with water features, like fountains or waterfalls, are simply gorgeous. However, some things can take away from their beauty. The foam that forms on the water’s surface and doesn’t dissipate is one of those things.
Some foam formation is normal and expected. After all, the movement of water is enough to cause the little bubbles to appear. That said, when it’s excessive, you’ll notice the pond water looks like it’s mixed with dishwashing liquid.
If the foam problem in your pond got out of hand, you might be wondering what can make it go away. It’s unsightly, to say the least, and can have downsides that affect the fish population in the pond.
So read on to learn how to get rid of pond foam naturally, as well as how to maintain your pond so the pond foam doesn’t reappear.
Unlike green foam that indicates algal growth, the white frothy appearance of pond foam almost looks like soap bubbles.
The white pond foam is the result of dissolved organic carbon (DOC for short). DOCs come from plants and animals in the pond. One of the main things DOCs can do is reduce the surface tension of water. But what does this mean?
Well, it means the water forms a thin film that can wrap around the air, forming the bubbles you see as froth floating on the water’s surface. That’s the same thing the surfactant does in liquid detergents like dishwashing soap.
You can also find it referred to as “protein foam” because it forms when there’s an excess of protein in the water. You can test for protein foam by checking the levels of nitrites and ammonia in your pond water
So why does that happen?
Pond water isn’t running water, which means it doesn’t have the same turnover rate as a stream or a river. With fish living in the pond, eating, spawning, and excreting, you’re bound to end up with some waste products in the water.
Here are the most common reasons why pond water foams:
When leaves, twigs, or other organic material fall into your pond, they start decomposing. The same goes for any dead fish you don’t remove.
The decomposition process, with the help of bacteria, breaks down the organic substances in the plant or animal material. The end products of decomposition are more water-soluble. When dissolved organic carbon rates rise in water, you get the frothing or foaming effect.
Feeding fish is just fun. It’s also one of the few ways you can interact with pet fish. Since the fish don’t seem to mind the extra food, where’s the harm?
Unfortunately, fish food that isn’t eaten sinks to the bottom of your pond and decomposes, much like other organic material. You can find this phenomenon increases during the winter months, and there’s a good reason for that.
Fish undergo torpor in the winter. The process is similar to bear hibernation, which means they don’t consume as much food, and when they do, their bodies don’t absorb the protein in it.
When you overfeed your fish, you’re not only wasting the food, but you’re also polluting the water they live in.
When your pond has the right conditions for it, your fish will start to get comfortable with each other. Fish spawning happens when there are enough plants to lay eggs in, food for the upcoming fish fry, and a decent temperature range.
Other than the foam, you’ll also notice some frisky activity happening. Male fish will bump into females, some fish will jump out of the water, and the pond might look like it has a slick sheen to it.
Most likely, the intense fishy smell will let you know the fish are going at it!
Keep in mind that if the fish population increases with no natural predators, the water could foam up from the extra fish in the pond. More fish means more waste.
The reasons we mentioned earlier for pond frothing can be somewhat less obvious if you have a strong filtration system. Poor filtration paired with excess organic material can intensify the pond foam issue and make it much more noticeable.
If you have a Koi pond in particular, you might want to invest in a large-enough pond filter. Koi fish are large in size and produce a lot of waste, overwhelming an inept filtration system.
Now that you know what could cause your pond water to foam up, here are a few ways you can naturally reduce the froth without resorting to chemicals.
The first step to minimizing pond foam is to know whether the chemistry is out of balance. Pond water test kits offer you a simple, but effective, way to check for protein byproducts in the water.
Ammonia and nitrites are called metabolic waste products. They form when animals digest proteins and come out in their excrement.
If your test kit shows a high concentration of ammonia or nitrites, you should go on with the next steps to reduce their concentrations.
Once you’ve tested your pond water, clear the pond of any decaying organic material. Use a manual pool skimmer to fish out twigs, leaves, trash, or anything else that doesn’t belong in the pool.
Use this opportunity to also sweep the bottom of the pond. This step removes sludge from fish waste and excess fish feed.
Some people notice a positive result after this step. However, sometimes it takes a little extra work.
As we established, excess fish food doesn’t do your pond much good. You should be aware of the amount your fish consume and try not to give them a lot more than that.
You’ve probably heard that fish consume all their food within a 5-minute window. So, a good way to measure how much you need is to feed them a small amount, wait till they’re finished, and top up. Do this for five minutes and look at how much food you have left in the bag.
As winter approaches, steer clear of high-protein fish food. Since their bodies don’t consume that much protein during torpor, it would pass right through them.
An overcrowding issue can make your fish pond extra foamy. A good way to fix it is to move some fish to a temporary residence like a blow-up kiddie pool.
The next step would be to check how that’s affecting your pond water. If you notice an improvement, find a new home for the fish you moved out. You can either build a new pond or donate the extra to a neighbor’s pond.
Let’s face it, no matter how much effort you put into keeping your pond clean, nothing beats a good filtration system. Unfortunately, too many people overestimate the power of their pond filter and then get surprised when it underperforms.
Choosing the right filter media is just as important as the power of the pond filter. There are cheap options on the market, but they rarely do their job as well as better-quality ones.
You should also invest in a pond skimmer, which should virtually eliminate most debris that falls into your pond. It can also remove the foam that builds up as it forms, making your pond cleaner and clearer.
You’ve done all the work but the progress is too slow for you. After all, your pond water won’t clear up in a single day once you’ve removed the root cause.
To accelerate the process, you can use a liquid pond defoaming agent. There are many available options on the market, and some of them are safe to use with fish. Just make sure the product blatantly says so on the packaging.
Pond foam can be unpleasant to see and might indicate a chemical imbalance in the water. Learning how to get rid of pond foam naturally is easy when you find the root cause and eliminate it.
Excess feed, fish overcrowding, and organic material in the pond can all cause pond foam. Using a powerful filtration system and a pond defoaming agent should make the foam disappear in no time.
Ben has a bachelor’s degree in construction engineering. When not constructing or remodeling X-Ray Rooms, Cardiovascular Labs, and Pharmacies, you can find him at home with wife and two daughters. Outside of family, He loves grilling and barbequing on his Big Green Egg and Blackstone Griddle, as well as working on projects around the house.
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