Hyper Fish!

Question
I have a 20 gallon fresh water aquarium and have it set up for about 6 or more weeks.  Things were going o.k. until I changed pumps to a 35-40 Whisper (Tetra) pump which has made my fish go crazy - and they will not come to the surface.  Even my albino catfish lays down at the bottom and when he does move around - it is really fast!  The 4 tiger barbs I have hang out underneath a fake plant - and if they do come out - they are hyper - like crazy! Their fins move fast also.  Could it be the pump - too big for my aquarium?  (It seems to be doing a nice job) or are the fish funny?  My two red tailed sharks are fine.  Thanks so much!!

Answer
Hi Debbie,
I believe I would do some experimenting on your aquarium to determine the exact cause of their hyperactivity.

I would try unplugging the filter for at least thirty minutes and see if they relax. Sometimes filters can produce too much high current in the water column and cause fish to retreat to the quieter portions of the tank.  

Its possible you can try positioning and anchoring plastic plants in front of the overflow of the filter to help lessen the force of the current.

Also check that no other fish are spooking them. Red-Tail sharks can bully. They can bully when you are not around to see. Since they are a territorial species I would suspect that they could be intimidating the other fish.  

Best of luck and I hope you can get the situation fixed with ease!
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