How To Keep Pond Water Clean Without Filter | Aquascape Addiction

How To Keep Pond Water Clean Without Filter

We cover the 10 best ways to keep pond water clean without using a filter, these are essential tips to avoid algae and diseases in your pond.

How To Keep Pond Water Clean Without Filter

You need to clean and maintain your pond. Now, some people prefer to not have filters in their outdoor fish ponds, mainly because of the cost and because outdoor filters can run into some big problems depending on the weather and climate.

Yes, it is possible to have a fish pond without a filtration unit, but you will need to find other ways to effectively clean it. After all, just because you do not have a filter does not mean that waste just does not build up.

Without a filter, things like fish waste, rotting plants, uneaten food, ammonia, nitrates, and a list of other contaminants can and will pollute the water. All of these things will hurt and kill your fish and plants. So, how to keep pond water clean without filter is what we are here to talk about today.

How To Keep Pond Water Clean Without Filter

1. Don’t Overstock The Pond

One of the first things to keep in mind when you are not using a filter is to not overstock the pond. By this we mean that you should not add too many fish into the pond. Fish eat a lot and they produce a lot of fish waste.

That waste is an eyesore, it mucks up the water, and it released poisonous compounds like ammonia too. The less fish are in the pond, the less waste is produced, and the less of these compounds will be present in the water.

Now, you obviously have your pond so you can have fish, so you do want to add a good amount, but if you are not using a filter, just do not overdo it. The amount of water in the pond compared to the amount of fish, when not using a filter, needs to be a lot higher than when you do have a filter.

Since there is no real way to filter these things out without a good filtration unit, keeping the fish population fairly low is necessary.

2. Don’t Overfeed Your Fish

The next thing that you want to keep in mind if you are not using a filtration unit in your pond is that you don’t want to overfeed the fish. If you overfeed your fish, there will be a lot of uneaten food present in the water. The uneaten food releases ammonia, nitrates, and nitrites, plus some other substances too.

These substances are harmful to fish, plus they can cause algae blooms too. This is also true for the fish waste itself. The more you feed the fish, the more waste will be produced.

Try to feed your pond fish just enough to survive, or a little more, but don’t spoil them with tons of food and treats that they won’t eat, or will eat too much of. It also helps to have the right kinds of foods, such as ones that do not contain phosphates.

3. Engage In Regular Water Changes

One of the best ways to help clean pond water without using a filter is to actually just change the water altogether. You can safely change up to 30% of the total water volume in the pond without negatively affecting the fish or plants. Removing the old water is really effective because you are directly removing contaminants and debris from the water this way.

Just be sure to dechlorinate the water and treat it so that it is suitable for your pond fish before adding the new water into the tank. Chlorine is very harmful to fish, so you need to be sure that the new water you are adding to the pond contains absolutely none of it.

4. Clean Your Pond Regularly

The next way to keep your pond water clean without using a filter is to clean it manually. Now, the most important aspect here is to clean away all kinds of solid fish waste, algae, uneaten food, rotting plants, and dead fish too. All of these things decay and release bad substances like ammonia into the water. Since you don’t have a filter, these things will just build up.

A great way to control these substances is to remove the things that create them in the first place. It is called being preventative instead of reactive. Also, you probably want to remove decorations, plants, and ornaments from the water every now and again to clean them as well. The cleaner you keep the pond, the less need there is for a filtration unit.

5. Use A UV Sterilizer

Now, when it comes to algae, a UV sterilizer will be a big boon for your filter-less pond. If you don’t have a good mechanical, biological, and chemical filtration unit, various substances which algae feeds off will build up, thus causing algae blooms.

However, algae needs a lot of sunlight to bloom and multiply, so using a UV sterilizer to neutralize the sunlight will go a long way in keeping the pond water free of algae. Algae does not look nice, it suffocates plants and fish, and it smells bad too, so this is definitely a big part of keeping your pond water clean.

6. Use A Nano Media Reactor

Ok, so this is kind of cheating, but whatever, it is not actually a filter. A nano media reactor is like a backup filtration unit that specializes in the removal of organic compounds like nitrates and ammonia from the water.

Yes, in a way it is a filter, which is why we said it is cheating kind of, but in reality, a filter and a nano media reactor are two different things. A nano media reactor is a great thing to have if you have lots of fish that produce a lot of waste. It is also an effective tool in terms of algae control as well. We have reviewed our top 5 here.

7. Use Pond Dye

Ok, so using pond dye is not exactly the best way to keep your pond water clean, but it does come with one main benefit. This benefit is that of algae control. Since algae need sunlight to thrive, blocking out as much light as possible will help control the algae growth (we have reviewed our top pond dyes over at this article).

Like we said before, algae stinks, it’s dirty, it discolors the water, and it suffocated pond inhabitants too, so this is quite important to keep in mind.

8. Have The Right Plants

Having the right plants in your pond is beneficial for keeping it clean too. Submerged plants act as natural filters and they help to draw out poisonous substances from the water.

Having a good amount of submerged plants in your pond will help to absorb waste products created by the fist. At the same time, having some floating plants will help stop some sunlight from making it to the water, thus also controlling algae growth (we have covered our 10 favorite plant options here that help keeping the water clean).

9. Take Advantage Of Cover

Sure, having your pond under a tree may cause leaves to fall into it, but that is not a huge deal in the long run. Having your pond under a tree will help to block out sunlight, thus controlling algae growth.

However, if you have a tree where lots of birds make their homes, you might want to avoid this, as bird waste is full of ammonia and you definitely do not want them to defecate in your pond (we have covered some tips here on keeping birds away from your pond).

10. Use Special Additives

The final thing that you can do to help keep your pond water clean without a filter is to add special additives to the pond, mainly beneficial bacteria. Beneficial bacteria will work to break down ammonia and nitrates, thus reducing the need for biological filtration.

It is actually one of the best ways to keep your pond water clean if you do not have a filter and do not plan on getting one.


As you can see, you do not actually need a filtration unit for your pond. Ok, so having a filter is definitely better than not having one, but if you engage in all of the tips and tricks we have discussed above, you should not have any problems keeping your pond water clean. Sure, it might be easier to keep a pond clean with a filter, but it is totally doable without one. That being said, you do need to be very diligent and cautious if you are going to go the route of not using a filtration unit in your pond.