is it possible to overfilter?

[crazycat]

newbie here

i'm setting up a 125 gal tank. i have an eheim knockoff filter that came with the tank and i want to put another filter on it as backup and as extra filtration since i don't really know the quality of the no-name filter i have--i'm looking at the fluval 404 (i have a 305 that i really like).

is it possible to overfilter a tank?

 

[Fishyfanatic]

You can never OVERfilter a tank. The more filtration, the better water quality. The only issue that arises is water current. Some fish can not tolerate heavy water currents that are sometimes a result of overfiltration. What types of fish will you be keeping?

 

[crazycat]

thanks for the info! the fluval 404 it is then.

i'll be keeping a school of denisonii barbs (10 @ 4" so far), plecos galore (12 and counting...), and a bunch of different types of cyprinids--drape fin barbs (oreichthys cosuatis), red shiners (cyprinella lutrensis), siamese algae eaters, and more (as the mood strikes me) probably some smaller tetras as well.

i'm also going to use 2 powerheads--one simply for current, and one attached to a pressurized co2 system.

too much current?

 

[Jchillin]

If you run both filters at maximum, you can create a whirlpool in your tank (only kidding, just very strong current). That much current can really stress fish. It would be wise to run them both at half flow, this will keep each one fully functional and eliminate the potential eddy from forming.

The math is @200gphx2=400gph...very stong output.

 

[crazycat]

what about the powerheads? at least the extra one--one is needed for the co2. too much current?

and just to make sure i have this correct:

the benefit of 2 filters is the additional biological filtration, which is unaffected by the flow rate. so if i decrease the flow rate on both to avoid stressing the fish, it's still better to have 2 filters as opposed to just one with max. flow rate?

 

[Jchillin]

As mentioned, you can never overfilter. Adjusting the flow rate will keep current normal. I don't understand the CO2 reference...are you planning on a planted tank? Or, did you mean O2 (ie: outflow surface agitation)?

You will adjust the outflow as needed, you don't have to have both at half max.

 

[krap101]

i think hes going to hook up some c02 to the powerhead to diffuse it

 

[megladonsharky]

Umm no overfilter possible..lol.. I have 80 plus on a three gallon with a beta in it... and a 9 ish gallon with 130-150 gph on it with a male betta

 

[crazycat]

yes, danny is correct. majorly planted tank. 3 wpg. need co2 system.

thanks so much for the info. i really appreciate it. but i'm still unsure whether i need an extra powerhead, just for water circulation, or whther the 2 filters at half flow will provide enough.

 

[Fishyfanatic]

I would say go with the 2 poweheads. It helps eliminate dead water. Dead water meaning water that isn't pushed around and filtered.

 

[dax29]

I have 400 gph + in both my 29's and all is well. I have much structure in the tank to break up the circulation and to give fish a place to rest. I have had no problems.