Can You Have Too Much Filtration In An Aquarium?

Filtration is an excellent way to eliminate toxic debris buildup in your fish tank. The more fish you raise, the stronger the filter should be.

But can you have too much filtration in an aquarium? This post will answer your question and share some tips for installing filtration. Let’s check it out!

Can You Have Too Much Filtration In An Aquarium?

The answer is No. Experienced fish owners always recommend the right degree of filtration. If not, over-filtering will lead to these problems:


The strong water currents will disturb the stones and plants in the tank. They will also drag the sand and substrate out of the floor once the water swirls.

The water will become cloudy too. Since it keeps flowing aggressively, the plants can’t settle. You will also notice that they always sway to one side.

Vision blockage

You will find it difficult to see anything in the aquarium with too much filtering. Expect the bubbles to get in your way.

Moreover, the strong currents of the filtration system will throw your tank decorations around.

Instead of a beautiful landscaping setup, your aquarium will become a mess.

Lack of healthy bacteria buildup

If the water is moving too fast, the tank can’ establish an appropriate layer of beneficial bacteria. Filtration for fish tanks must cycle itself by producing bacteria.

Once the filtration systems have sufficient bacteria, they can regulate the water and inhibit the formation of too much algae. The germs can’t rest if the water is going too fast.

Different requirements among species

Filtration is more important for some species than others. For example, cichlids need strong filters because they become filthy after eating or pooping.

So if you raise these stunning fish, consider investing in more infiltration.

aquarium filter

Over-filtering will cause many problems

How Much Filtration Should An Aquarium Have?

You can’t have too much filtration in your fish tank. However, your pets will face poor water conditions if they can’t filter all accumulated waste.

So how much filtration is enough?

Your aquarium’s water should go through the filtering system at least four times every hour. Always switch to a higher rate when it’s closer to it.

For instance, a 30-gallon tank demands 120 gallons per hour (gph) flow rate. You should get the 150 gph filtration if the alternatives are 100 or 150 gph.

Proper filtering also depends on two criteria: how robust the system is and how many fish you keep.

How do I know if my filter is too strong?

If you have sensitive pets, a filter can be too powerful for them. Some may become stressed as a result of the fast-moving water.

Signs of an excessively strong filtration are:

  • The fish try to swim close to the floor of their tank and don’t want to leave their hiding places.
  • The filter is too strong if it moves fish, plants, and sediment too far and in one direction.
  • Gourami fish lay eggs in bubbles on the surface. Yet, a powerful will break the bubbles and prevent your pets from reproducing.
  • Your fish, plants, and decorations get stuck in the filter.


Your fish do not like the excessively strong filter

How do I know if my tank is overstocked?

The filtration should adapt to the demand of your fish. Often, if there are more species, fish owners install more filters or choose a more robust system.

As a result, you can tell whether you have proper filtration for your pets by considering your tank population.

The best rule is to avoid overstocking. Otherwise, even a strong filter can’t work.

Here are some signs to determine if you have overstocked your aquarium:

  • The water gets dirty easily even after you clean it.
  • There is a shortage in the oxygen supply. You can see your fish gasping continuously.
  • Excessive discharge of ammonia and nitrate will result in the development of algae in your aquarium.
  • Your pets have weird behaviors, such as swimming at the bottom, breathing on the surface, or hiding on rocks and plants.
  • Diseases can spread quickly across the tank. The most common diseases are white spots, gill flukes, or rotting fins.

This video will show you some tips to deal with overstocking:

Is It Okay to Have 2 Filters in an Aquarium?

Yes. You can install two filters in your tank, as long as they don’t disturb your pets. However, there are still downsides to employing this method.

Let’s check its pros and cons before starting your project.


  • If one filter breaks down, the other will still work to keep your tank filtered continuously.
  • One filter can work to prepare and cycle for bacterial development, building up a healthy layer of bacteria. During this time, you can set up another tank.
  • Some species require more filtration than others, as aforementioned. If you raise goldfish, cichlids, or any messy species, installing an additional filter will be an excellent solution.
  • If your tank doesn’t have sufficient biological filtration and you can’t clean it frequently, you will need another filtration system.
  • A weak filter can’t handle all the waste in your tank. In this case, another filtration system of the same size will help.


  • There will be a higher risk of over-filtering.
  • The extra filter takes up more space. Your pets can’t swim freely as they used to.
  • You have to work more when maintaining and cleaning two filters.
  • Some species, like snails, tend to avoid filtration systems.

fish tank with plants

Consider whether your fish need two filters


Filtration is a big help in dealing with debris in your aquarium. However, if you don’t know how to use it correctly, there will be more problems in the future.

Over-filtering and insufficient filtering are both unpleasant to your pets. So try to discover how much filtration they need before installation.

Hopefully, our post can help you provide the best conditions for your lovely fish. If you need more tips, please comment. We will reply to you as soon as possible.