Rapid breathing - to much filtration?

I put up my new sump in sunday haven't had chance to post designs etc but I have been running it with all the previous filter media at around 150 lph and the fish were all doing well o thurs I decided to crank up the speed to around 350 lph I have noticed friday morning that some of the corydoryas have been breathing a bit rapidly and the weren't acting as they normally do I noticed today the otos were also breathing a bit rapidly I turned down the speed back to 150 lph and it seems that all the fish have returned to normal. I have the 8l sump(2l of filterwool,potscrubbers,bioballs and ceramic rings) and a large internal filter running to supply biofiltration in powercuts could I possilby have had to much filtration for my 72l tank and this was causing the strange behaviour as I only noticed the odd behaviour once the filters speed was increased. None of the fish were hovering near the surface or gasping for air it was just rapid breathing and they were a bit lethargic. Any ideas thanks guys.

 

I would guess at one of two things...

Firstly, lack of oxygen in the water. This could be the case, but your pump should disturb the water surface enough that oxygen can be exchanged at the surface??

Secondly, the current is to high for the fish. 350L/H sounds pretty high for a 72L tank! The fish are most likely breathing rapidly, from trying to stay in the same place?

So more of a case of over circulated and under oxygenated rather than over filtrated?!

They would be my guesses, but I'm sure someone more knowledgable (and probably a couple less knowledgable) will tell you and talking through my butt?

Regards
G!

 

:smile1:

I think 216L/H should be the most to crank it up too/to,make sure you something is disturbing the water surface because when the surface of the water is broken air is allowed in to oxynate the water.