Hello - I recently completed a fishless cycle in my 54 gallon tank. I have stocked it with 10 harlequin rasboras and 11 neon tetras, and then on Tuesday my LFS
will have in my honey gouramis and 15 pygmy cories. I have a Rena Filstar XP3 filter.
The filter was absolutely blowing around the poor neons and rasboras. I gave them overnight to see if they would get used to it, and they just kind of huddled in the far corner away from the filter outflow. So I put a prefilter sponge over the outflow - I also have one in the intake. If I put my hand near the outflow, I can definitely feel the current. But the sponge just disperses it. The second I put the sponge on, the fish started schooling all over the place, exploring happily.
My question (sorry for the long explanation) - is there such a thing as too baffled?? I don't think it's actually slowing down the flow of the filter in any way as to put strain on the motor/etc. The sponge just slows the current. But am I running an oxygen/gas exchange issue now? I have one airstone in the far corner of the tank, and I'm going to get a new air pump so I can run another stone in the other corner - I have a splitter, but my pump is only powerful enough to run one. I don't want the water to become stagnant, but I also don't want the poor little guys to feel harassed. The surface of the water has a slight movement, and I'm thinking the second airstone will help with that. Should I take off the sponge?