How To Tell If Current Is Too Strong For Fish? 3 Clear Signs

Do you want to know how to tell if current is too strong for fish? This is necessary to help you identify the negative effects on them. Also, you can find effective solutions to improve it.  

This article is the right landing spot, giving you useful information about the signs of intense water current in your home aquarium. Besides, we also suggest simple methods to reduce the strength of water flow and protect your fish. Let’s read on for details!

How To Tell If Current Is Too Strong For Fish?

You can determine if the current is too powerful through common signs such as difficulty swimming, constant hiding, and floating, or fish seeking for a calmer place. Below are the clear indicators to tell you about the strong water flow.

group of fish

Difficult To Swim In A Straight Line

The water stream in the tank is also too powerful if your fish struggle to swim in the direction they want. Instead of swimming as usual, they will move around in aquariums. So if you find their gliding difficult, you should seek a way to slow down the flow.

This sign is also because the stream pushes your fish in random directions while they must try to swim against the water. Thus, they will look for locations with lower flow speeds when the current is so strong.

Struggling to swim is not good for their growth. Thus, you need to monitor this sign to adjust some elements, such as water flow speed in the tank or filter settings. 

It is essential to check whether they are having difficulty swimming in a straight direction. If you see it takes the fish a longer time than normal to move just a little bit or their swimming path is no longer a straight line, it means the current is so strong.

Constantly Hiding Inside Decoration Items Or Floating

Another sign of this problem is your fish wants to hide constantly among the decorations inside the aquarium. They want to sidestep the fast water current if you find them floating over the decorative templates or hiding in plastic plants or cave structures. 

Besides, they also need a place to stay still and relax, and they can seek hiding spots with the slower water flow.  

Sometimes, they can hover around the tank’s top or bottom, including dead spots. This is a sign that tells you the flow is too intense.

hiding guppy

Your Fish Avoiding Some Areas

You sometimes see that the fish always avoid certain areas in the tank. This sign also tells you about the fast water stream speed that comes from those zones. They may find and live in another place since it is difficult to swim near powerful currents.

What Will Happen if Water Current Is Too Strong for Fish?

Below are what will happen to your fish when they face the too-strong water current in your aquarium.

You need to know them to have the proper method to care for them. 

Health And Stress Problems

Your fish can feel stressed when they must fight a powerful water flow in the tank. If stress continues unabated and lasts, it may cause danger for these species, even killing them. 

The stress also leads to health problems when they refuse to eat, and stressed fish are susceptible to disease and die sooner.

Damaged Scales And Fins

Their scales and fins can get damaged when they struggle to move against the water flow.

The fast stream speed can make them hit the walls and interior decorations in the tank, even leading to death. 

Stay In One Place 

You will find that they can be cramped in one place in the tank. This place may be a corner in the tank or a hiding area with many ornaments for them to hide the strong water flow. 

Overcrowding one spot might make them lack oxygen or food.

Stay In One Place 

How To Fix The Strong Current For Fish?

First, purchasing the correct filter for setting in the particular aquarium is always a good idea. Yet, if you want to upgrade your aquarium next time, you can choose a filter that enables you to adjust the water flow. 

Some practical ways below also reduce flow performance. They are simple and economical solutions you can apply to improve the speed of the water flow in the aquarium. 

  1. Add rocks, caves, or plants around the tank. This can distract, slow down the flow, and reduce the strong power of the direct currents. In addition, these components can generate crannies and nooks for these species to relax and hide. 
  2. Use the current filter control. Several filter models, including hang-on-the-back ones, come with built-in settings that give better water flow regulation.

fish with decoration things in aquarium

What Is The Ideal Water Flow For A Tank?

It depends on your specific tank. Neon tetras or cardinals may thrive in turbulent currents. Strong currents in a tank may push aquarium plants aside or lean forward. This can be seen as unnatural for them. However, some species prefer calm water, such as discus, fancy guppies, or goldfish.


How to tell if current is too strong for fish? Now you’ve answered. You can notice some popular signs through your fish in the tank. They can avoid the powerful flow, struggle to swim in a straight line, and hide among decorations. 

If these problems last, they will affect your fish’s health, appearance, and spirit, such as damaged fins and scales, stress, or hiding in one spot. They also refuse to feed, illness, or even die. 

Thus, it is necessary to find the proper ways, through useful guidance in this article, to slow down the flow in your tank.