[lambretta]

i have 3 internal filters in my tank just because i had them an they move the water around

on the last water change i push one down to the bottom and forgot to push it back to the top
now instead of all the mbuna hiding in the rocks at the back of the tank they are all at the front lining up in the output from the filter and jostling for the best position whatever that is
wife thinks it looks like a queue of cars waiting for the lights to go green

 

[DJRansome]

Extra oxygen? Do they have enough oxygen in the rest of the tank?

 

[lambretta]

plenty
2 other internal filers aimed at the surface and really moving it about plus spray bar from external filter aimed at surface
no sign of any fish struggling or hanging around the surface

i know from fishing that fish hang around behind rocks or in weeds facing the currents to catch any food being brought down stream

 

[DJRansome]

Agreed and that is supposedly an osygenation issue. I guess you can never have too much. :thumb: