Aquarium Filter Current Too Strong – How to Fix This Issue?


Although filter currents are way too crucial for aquatic life, it is essential to maintain optimal water speeds in aquariums.

Aquarium Filter Current Too Strong – How to fix this issue? If you are sure about Aquarium Current being strong, we will help you in understanding how to fix this issue. Some of the best ways to impede strong filter currents are: Adjust the filter’s flow control, revamp the space with caves and rocks, introduce live/artificial plants and install DC-return pumps etc.

Hobbyists and new aquarium owners facing trouble in identifying whether the water currents are too strong, here’s what you can do.

Fixing Overly Strong Aquarium Filter Current

Just as every natural habitat has its pre-requisites to support life, aquatic habitats demand a consistent water current for several reasons.

It is rightly said that still water bodies can hardly support any life, indicating the importance of suitable water currents for supporting aquatic life.

There is no harm in being unfamiliar to the requirements of owning an aquarium as even the most experienced people find themselves at crossroads while determining suitable water currents for their aquarium.


You may be wondering why do filter currents are vital to aquarium keeping.

Here are the top reasons as to why water currents are essential for fish keeping:

  • Filter current stimulates the consistent circulation of water in your aquarium.
  • It helps in dispersal of dissolved oxygen in all corners of the aquarium
  • It promotes surface agitation which is paramount for gaseous surface exchange
  • It maintains an optimal temperature in the aquatic environment
  • It helps in uniform distribution of food and beneficial bacteria in the aquarium
  • Filter current boosts physical activity in fish to keep them active
  • It also supplements the filtration of water for the removal of harmful substances
  • It helps fish in proper feeding

The role of filter currents is as crucial as surface agitation when it comes to supporting aquatic life.

You may have seen water filters installed near the water surface of submerged in tank water.

Considering the prevalence of water filters in aquariums, many people opt to get one for their tanks as well.

The question is:

Is getting a water filter enough for healthy fish keeping?

Contrary to the common misconception of sailing close to the wind by neglecting filter current adjustment, the ideal way to deal with this issue is to pull your sock’s up and make suitable adjustments.

Critical Indicators of Overly Strong Filter Currents

Many people assume that as long as bubbles are popping on the water surface, filter current is maintained optimally.

But here’s the kicker:

If the filter current hampers or disrupts natural swimming movements of any fish in the tank, it is time to throw it away, adjust the flow rate, or replace the apparatus altogether.

Some critical indicators of unbearable levels of filter current for fish include:

  • Fish may flop over vertically or horizontally
  • They will face trouble in moving at whatever speed they choose
  • Fish with larger fins could exhibit retarded rates and dangling movements
  • Betta fish will struggle to move at an angle and present aberrant pushing of the rear end towards the front
  • Some fish will resort to hiding out behind plants or in caves as swimming becomes more and more challenging
  • Overall, the fish could be seen struggling to maintain balance while swimming.

Dangers of Excessively Strong Aquarium Filter Current

There are more than one instances reported by aquarium experts when one of their fellow hobbyists failed to identify the excessive Aquarium filter current, resulting in the death of fish.

Here is the deal:

  • Rapid currents can disrupt the uniformity of aquarium altogether
  • They can cause excessive bubbling on the surface which can induce a “hazy effect” which will harm water clarity
  • Rapid currents make it harder for fish to locate and catch the meals
  • Excessive turbulence causes uneven distribution of useful bacteria


If you really want to look after the well-being of your fish species, it is best to maintain optimal levels of filter current in your tank.

Feed Your Wish Well

Better feeding is probably one of the most significant reasons to control filter current in your tank.

You will be surprised to know that the current speeds have a significant impact on determining your fish’s feeding ability as slow-moving water offers better chances for these tiny creatures to move swiftly towards feeding area.

On the other hand, faster currents suppress the feeding ability of slow-moving fish as aggressive ones tend to move faster and finish the meal before anyone else reaches the feeding spot.

It gets worse:

Extra strong currents can cause extreme discomfort and malnutrition, leading to sickness and ultimately death of inhabitants of a fish tank.

So, when it is feeding time, don’t forget to reduce filter current in your fish tank.

Ways to Impede Strong Aquarium Water Current

Hampering water currents in aquariums is quite inexpensive and straightforward.

You can conserve the life and health of your favorite fish by spending some effort and a few bucks.


As we have established that strong water currents are merely threatening to fish life, let’s have a look at all the possible solutions to this problem:

Flow Control

Flow Control adjustment is the simplest and easiest method of impeding excessive water current.

If you have installed an external filter in your tank, a flow control knob is very likely to be present in the apparatus.

You can turn the knob in any of the two directions in order to adjust the filtered water flowing in and out of the filter at a suitable rate.

As a result of the reduction in the water flow rate, the water circulation will be reduced to assist in lowering the strength of water currents.

But here is the kicker:

This solution is only applicable to air filters as impellers do not feature any similar adjustments, commonly.

Rocks and Caves

Naturally, the role of rocks and caves is same as barriers which not only redirect water flow but also disrupt the flow patterns to stimulate a reduction in water current speeds.

Here is the deal:

Some fish species prefer to live placidly under the shelter or caves and rocks.

You can install high-quality natural rocks and cave-like structures in your aquariums to create pockets in some places so that your fish can enjoy effortless floating.

Artificial or Live Plants

Plants have long served as a mean of enhancing the aesthetics of decorative aquariums.

Want to know the best part?

Artificial or Live plants can also help in impeding excessive filter currents.

The groovy structures and rough surfaces of these plants help in creating quiet zones for fish to enjoy an interrupted time inside the fish tank.

DC-Current Return Pumps

Although relatively new, the DC-Current return pumps are excessively gaining popularity when the matter of controlling filter currently in tanks is in question.

A motor speed control present inside these pumps helps in achieving precise control over the flow rate of water currents.

You can adjust water flow and current movements by using these pumps.

Related Questions

Can an overly active filter kill my fish?

Yes, it can.

Here’s the deal:

Water filters tend to create turbulence in the still of tank water. As a result, fish have to exert force in order to overcome this turbulence for the sake of getting meals and enjoying their time overall. While some fish have higher tolerance towards alleviated levels of physical activity, others fail to meet this demand. As a result, they feel exhausted and eventually, die. This situation holds true for even the toughest of fish species. In order to avoid any fatalities, it is best to adjust filter current in your tank.

Why are my fish always swimming closer to the filter?

They just want to live happily!

Like most organisms, the primal instincts in fish make them pursue an easier life. There are two reasons as to why your fish like to hand out near the filters:

  • Spaces near filters in a fish tank are spots of faster water flow. It indicates that these areas have maximum levels of oxygen, which can be readily taken up by fish gills.
  • As opportunistic feeders, fish prefer to hand out near the food instead of putting in effort for preying. Therefore, they hang near the filter.

When can a filter be too strong for Goldfish and Betta? It all comes down to the size of the tank.

Goldfish and Betta fish are among those species that can live happily in small spaces. The only major problem with fish bowls or small fish tanks is the limited surface area available for gaseous exchange (aka oxygenation). If you have a tank which can support 2.5 gallons or lesser water, avoid using water filters as it can generate too strong Filter currents. It can result in excess levels of stress for your Goldfish and Betta species and result in making them sick.

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