Has your small pond developed algae that is spreading out of control? Maybe this is the first time you have encountered algae and you aren’t sure what to do?
Or are you looking for the reason why algae has spread? Whatever reason brought you here today, we have the answers you need!
We know how frustrating it can be when your small pond develops algae. At first, you think that it’s normal and just part of your life as a pond owner now.
But when it starts to spread, blocking light from entering the pond, you start to worry. Could this algae be killing your pond (see also ‘ 3 Actions For What To Do With Your Unwanted Pond ‘)?
What about the little lives that live beneath the surface? You start panicking, searching and searching for answers, but you can’t find the ones that you need.
Well, no more! Today we are here to help. Just keep reading to find out the best ways that you can control small pond algae!
We will walk you through the types of algae, methods of control, and anything else you need to know.
Types Of Algae
Before we dive into showing you how to control your algae, let’s start by looking at the different types of algae.
There are hundreds of different types of pond algae that you could find in your small pond, but the two most common are string algae, which looks like long green hair, and planktonic algae, which looks like green pea soup.
Let’s dive in and look a little closer at each type.
String Algae
String algae tend to grow at the bottom or edges of your pond, where there isn’t much water circulation. It’s a pretty simple algae and you can kill it with Green Clean pond cleaner.
The cleaner is safe for use in ponds with fish, or other water features in your garden, and oxidizes and destroys the cell structure of algae.
You can expect to see results within 48 hours with this cleaner, and it isn’t too expensive either!
Planktonic Algae

Planktonic or plankton algae is the most common algae we see in ponds and lakes. This algae gives the water a green look that makes it hard to spot fish or other wildlife in the pond.
Now, to get rid of planktonic algae, you first need to understand why and how it grows.
For planktonic algae to grow, it needs two things, nutrition and sunlight. Sunlight will come from the sun, and there’s not a lot we can do about sunlight!
The nutrition, though, comes from decomposed fish food, dying plants, weeds, decaying plants and weeds, byproducts from fish waste, and any chemicals or fertilizers that might have made their way from your garden into your pond.
We normally see chemicals or fertilizers fall in if your pond is at the bottom or lower part of your yard.
The best way to get rid of planktonic algae is to either reduce the amount of sunlight your pond gets, or to starve the algae of nutrients.
We will walk you through how you can do this now.
Blocking Sunlight From Your Pond
The easiest way to reduce sunlight to your pond is by adding shade. You can do this with plants like water lilies or floating plants like hyacinths.
These plants will cover the surface area and also make your pond look prettier! Who doesn’t want to see a pond with beautiful lilies floating on top?
Another option is an aquatic sun blocker. Aquashade is a fine option that dyes your pond to help disrupt the sunlight entering your pond.
The idea behind this is the darker the water is, the harder it will be for sunlight to enter, starving your algae of sunlight.
Aquashade is super easy to apply and is proven to limit sunlight to plants under your pond’s water.
Not only will this help with algae control, but other weeds or plants at the bottom of the pond that you don’t want.
Reducing Nutrients From Your Pond
Your second option is to reduce nutrients from your pond that algae can feed on. There are a few options here that you can explore. First, you will want to clean your pond (see also ‘How To Keep A Pond Clean Without A Filter‘).
This is the best way to remove dead and decaying leaves that could be gathering at the bottom of your pond or along the sides.
You can do this yourself, or hire someone to clean the pond if you wish.
For small ponds, it’s usually quite easy to clean the pond yourself and it shouldn’t take you too long to do either!
Once these are removed, you can use a skimmer to remove any leaves or debris before they have a chance to settle at the bottom of the pond!
Other options include a Pond Net which you can use to cover your pond.
The netting across the top of the pond will help prevent any debris or leaves from falling into the water.
Netting is also a fine way to keep predators from your pond.
Now you won’t need to worry about raccoons or other birds diving into your pond and pinching your fish.
It’s worth clearing any debris on your net every day or so to prevent build-up.
Of course, this will vary depending on the location of your pond and how much debris it collects.
For example, if your pond is beneath a tree, you might clear leaves more frequently than if there were no trees nearby.
Once the pond is free from debris, you will want to add some beneficial bacteria to the pond.
When it comes to bacteria, there are two kinds, the good kind, and the bad kind.
Bad bacteria can harm your fish’s health, eating away at their gills, and skin, causing sickness and eventually death.
And no one will want that happening to their fish!
Good, or beneficial bacteria, will work to break down ammonia from fish waste, but turn it into nitrates.
This is also known as the nitrogen cycle and is something you want in your pond!
Beneficial bacteria will also consume the same nutrients that algae do. And if the bacteria are eating the nutrients, then the algae can’t!
By adding beneficial bacteria to your pond, you will starve the algae. Once the algae are starved, they will die and you can enjoy a clearer pond.
Not only will it remove your algae, but beneficial bacteria can clear the sludge or muck at the bottom of fish ponds, koi ponds, and more!
It’s a vital part of having a clean pond to add beneficial bacteria to the water.
So how can you do it? Well, you can purchase beneficial bacteria from garden stores or online.
You will want to check the instructions on the packaging to know how much of the solution you need depending on the size of your pond.
You will also want to check quickly that the bacteria is safe to use with your fish. In most cases, it is, but it is always best to double-check before you use it!
For beneficial bacteria to grow in your pond, you will want to establish a biological filter. You can do this by adding plants, rocks, and filter media to your pond.
Again, you can purchase these materials online or at a garden store. You will want to ensure that the filter media is suitable for your pond and any wildlife in there.
There tend to be specific filters for koi ponds, so be sure to check before you add it to your pond that it is the correct filter.
It can take anywhere from three to eight weeks for a colony of beneficial bacteria to be established.
But by using store-bought beneficial bacteria, you can speed this process up! For smaller ponds, you won’t need to add too much either.
You can follow the instructions on the packaging to ensure that you are adding the correct amount too.
Can I Use Algae Killing Products To Get Rid Of Algae?

Now, you are sure to see online or in-store a whole bunch of products that claim to kill algae.
Products like ALGAEFIX are incredibly popular and often top the bestseller lists on Amazon.
But are they worth purchasing?
Well, they work to control planktonic algae and string algae, but they will also work on other types of algae too and prevent any ornaments from getting covered in green algae.
But, you will regularly need to add them to water.
Most of these treatments require to be added every few days at the start and then weekly to keep your algae under control.
Once you stop using the algae killer, the problem is going to return. Rather than ‘killing’ the algae, it just seems to keep it under control.
If you are happy with the regular maintenance and keeping the algae at bay, then this can be a fine choice for you.
These algae killers are also a good option if you would struggle to empty your pond, clean it thoroughly and refill it.
Store-bought killers like this are a good choice for those that don’t have the time to do too much maintenance to your pond.
If you are thinking these killers are a good choice for you, or if you want some more information, then read on.
These killers generally work by killing your algae.
Next, your algae are supposed to filter through your water, dispersing it and preventing it from re-growing.
Instead, what happens is the dead algae builds up at the bottom of your pond.
This creates an organic compost pile. While that can sound good, it’s the worst thing for your pond!
The dead algae in the compost pile will give off plenty of nutrients that will promote more algae growth!
Give it a few weeks and your algae will be back to its previous levels, spreading across your pond!
Not what you want when you have spent your hard-earned cash on a product that is meant to kill your algae.
You can get stuck in a cycle with these algae killers. You can find yourself killing the algae, only for it to be back in a few weeks, needing you to use more!
You end up providing the algae with more and more food, promoting it to grow rather than die!
That is quite literally the opposite of what you want your algae killer to do.
Because of this, we recommend that you avoid purchasing these algae killers. We know they can seem tempting, and for some people, they can be the only option.
But where possible, we think it is best to clean your pond out and then add beneficial bacteria to your pond.
This way, you can create a colony in your pond that will kill the algae and prevent it from growing again.
You are also opting for a lower or chemical-free option too, reducing the chances of your fish or other wildlife getting sick.
Final Thoughts
And there you have it!
The best way to control algae in a small pond is to clean out any debris, waste, or decaying matter from your pond and introduce beneficial bacteria to ensure that your algae are starved of nutrients and kept at bay.
You should also consider adding some water plants that will block sunlight from your pond, preventing algae or other weeds from growing underwater.
For those whose ponds are near trees or attract a lot of debris, we also recommend covering your pond with some netting.
Not only does this mean you can spend less time clearing debris away, but you can protect your pond’s animals from predators like birds and raccoons.
Thankfully, keeping your pond free from algae isn’t as challenging as you first thought!
With some regular maintenance and cleaning, you can transform your pond and banish algae for good!
Before you leave us today, be sure to check out our FAQ section below where we will answer any last-minute questions you might have.
Frequently Asked Questions

As promised, we have an FAQ section for you! Here we will tackle any of your last-minute algae-related questions. Let’s get started!
What Naturally Kills Algae?
You can use some baking soda to naturally kill algae. This works well with most types of algae and can be applied with a brush to the affected areas.
Once you have applied the baking soda, the main ingredient of bicarbonate will get to work.
You should be able to loosen algae from any walls or sides of the pond, lifting it from the root and removing it.
This method tends to work better in drier areas or on the walls surrounding a pond rather than the bottom of the pond.
It can also be tricky to use this method with black algae, as it tends to be incredibly stubborn and the roots are difficult to remove.
How Can I Keep My Pond Water Clear?
There are a few ways that you can keep your pond water clear. The first is one we mentioned earlier, and that is beneficial bacteria.
It will work to starve algae and remove the green color from your water.
You can also add more plants which will work to starve algae further, especially by blocking out sunlight.
Another popular option is to add a biofilter or replace your current filter with a larger one.
This will ensure that as much debris and waste is pulled from the water as possible and that only clean water is entering your pond.
The size of the filter you will need will vary depending on the size of your pond. Typically, smaller ponds don’t require large filters.
You should also avoid overfeeding your fish. Any fish food that isn’t consumed, as we know, makes its way to the bottom of your pond and starts to decompose.
And when it starts to decompose, it can release nutrients that algae will thrive off! Feed your fish only what they need to eat.
If you notice there is a lot of food at the bottom, reduce the amount of food or times you feed your fish.
Finally, you will want to avoid overfilling your pond with fish.
If you add too many fish, not only will your fish not be comfortable, but there will be more waste in the water.
This can be harmful to your fish’s health, but also promotes more algae growth and leaves the water looking dirty or green.
Will Removing Algae Harm My Fish?
No, if you have followed the advice we have given you today, then removing the algae from your pond should not harm your fish.
Remember when emptying and cleaning your pond to place your fish in clean water while you do this and to check that any products you use are safe for fish.
This is the best way to ensure the safety of your fish and enjoy a clean pond.