I just set up a filter on my 10 gallon tank (a Tetra Whisper PF10 filter with a medium BioBag cartidge). Everything is working perfectly, but my betta fish, Swimmers, is struggling to swim to the other side of the tank.
I have been checking on him every half hour and it looks like his two tiny fins near his face are swimming at warp speed, trying to work against the waterfall affect. I tried a tip I found on YouTube that you take a water bottle that the ends have been cut off and the middle is cut lengthwise and put under the filter and the cover. It won't stay and just sinks under the weight of the waterfall.
I don't know what else to do, but I don't want Swimmers stressed again. I just got him to eat normally and got his fungal infection cleared up. Any tips?