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An Easy Fix For Aquarium Currents Too Strong For Betta Fish

A friend invited me over to check out his new Betta fish he just added to his 30 gallon aquarium. Of course I took him up on this and ventured over to check out this new beauty. I walked into his living room and the exact moment I looked at the aquarium I could tell the Betta was having difficulty swimming.

I knew immediately that the Aquarium filter was too strong for the fish. It looked like the water was pushing the poor little fish off balance every time he swam at the end of the tank that the Aqua-clear filter was hanging on. I also noticed a power head on the other side of the tank creating even more of a current and difficulties for the Betta to swim.

I told my buddy his new Betta fish looked beautiful and then proceeded to mention the problem with the strong current. My friend agreed to fix this so the fish would not be stressed.

The solution to reduce the filter current I recommend is to create a DIY aquarium filter baffle for an aquarium filter that hangs on the back of a tank. Baffling a tank filter for Bettas is the thing to do unless you have a tank filled with live plants as well then that should cut down on the strong water current.

Let me make this clear, the issue isn’t that the aquarium filter is too strong because all filters are created to process water through the filter according to the size of the tank. As long as you purchase the correct size filter for your aquarium the tank will be fine.

The issue is that some fish like Betta’s and Angelfish for example do not swim well in strong or fast moving water currents. Their natural environment is in calmer waters and it is your job to ensure you replicate that environment to ensure happy healthy fish. This is one of the problems when placing Betta fish in very small aquariums is that the water is usually flowing to strong. When placed in a larger aquarium the water flow can be controlled better for these types of fish.


How to Make an Aquariums Current Less Powerful for Your Fish

So the current is too strong for your Betta. Here is what you can do. You must baffle the tanks filter to reduce the strength of the current. I saw this quick and easy fix somewhere online and it stuck with me. It shouldn’t cost you anything which makes it even better. That is one of the benefits of a DIY filter baffle.

Let’s just touch on what a Baffle is quickly. A baffle is something that regulates and or restrains the flow of water. That’s basically it for this application.

reduce fish tank current with this trick

What You Will Need to Accomplish Baffling Your Aquarium Filter is;

  1. A clean used water bottle (you could even use a plastic pop bottle if you have one that is less than a liter).
  2. A pair of scissors or a utility knife will be required to cut the bottle open.
  3. You might need packing tape (or some other strong tape, painters tape probably won’t work for this application) but only if the bottle doesn’t sit where you want it too.

Yes that is all you need. You might not even need the tape if the plastic bottle will sit nicely on the filter without falling into the aquarium.

The next step is to cut the bottom and the bottle neck portion of the water bottle off. Be careful with those scissors.

After that is done cut through the bottle lengthwise so when looking at the bottle from the end it looks like Pac Man.

Once you have all of your cuts done just make sure there are no small loose pieces that could fall off ending up in a fish’s mouth.


To install your new aquarium filter baffle you should probably turn the power off to your filter to avoid making a mess. With water bottle baffle in hand horizontally take the open end hooking it under the bottom of the filter spout or mouth then placing the other side of the baffle onto the top portion of the filter or where it will rest without pulling away.

You might need a different size bottle depending on the size or your filter so this will be a trial and error type process. If you find the bottle fits nicely on your filter you might want to place a piece of packing tape on the top piece ensuring it stays and does not fall off once you turn your filter back on. Just use your better judgement when selecting the size of bottle to use for this project.

Now that you have your baffle installed turn your filter on and watch how the water now flows out of both ends of the water bottle baffle thus reducing the current.


You’re Betta or whatever fish you have will be much happier now.

How to Tell if the Water Current is Too Strong for Your Fish

If the flow in your freshwater aquarium is too strong it should be very obvious unless you are such a newbie to the aquarium hobby and have not really spent much time watching fish swim in tanks. Fish should be able to swim at whatever speed they want without being flopped over vertically or horizontally. When a fish has larger fins this can be an issue when water current is a bit strong. The way to easily identify if your water current is too strong is to look at how your fish is swimming. Does it look like the Betta is swimming on an angle or does it look like its rear end is being pushed around to its front? In general if the fish looks like it is struggling at all then the current is probably too strong.

Some fish will hide out in caves or in plants because swimming out in the open is just too challenging.

Other Ideas to Slow Down the Current

  • Purchase quite a few live plants placing them strategically around the area that the water filter pours the filtered water back into the aquarium. Remember that you want to slow down the water and not stop it so that the aquarium does not get filtered properly.


  • Purchase a large aquarium decoration placing it under the area that the water is poured back in to the tank. Make sure the decoration is at least a couple inches under the water. If the water level drops enough it will start splashing on the top of the decoration spraying out onto your floor. If the decoration or rocks are large enough the water will disperse over the area slowly down the current in the water but allowing the filtration system in your tank to do its job.

Back to my buddies aquarium. We made a plastic bottle baffle as well as taking out the power head at the other end of the aquarium from the filter. His Betta fish (Thor) looks to be very happy and settled now.

Just remember when looking at your own aquarium that if the water current looks to strong for your fish then it probably is.

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