View Full Version : cannister filter gph(tank size specs.)???
snookers
09-16-2003, 7:08 PM
What should the GPH turnover be for cannister filters, related to tank size requirements/ideals?
Does a tank need less filter turnover 'cause it's a cannister and not HOB(bio wheel type)?
Andy16
09-16-2003, 7:23 PM
I wouldnt make the GPH turnover lower just becasue you have a cannister. IT should be 8-11 times per hour nomatter what. Cannisters might be more effective, but i wouldnt want to cheap out on hte filtraiton system.
It all depends on the efficiency of the particular brand. I use Eheims, which are highly efficient devices, and the company suggests canister size based on the high efficiency of their units. I have never found my tanks to be underfiltered based on their suggestions, in fact they are very comfortably over-filtered. I tend to pick units in the middle of their suggested range, so that if they say a particular unit is good for tank from a to e gallons, I'll use that unit for tanks of c gallons - the center of the range.
They detail their flows on their website:
Eheim site (http://www.eheim.com)
You will find that these are nowhere near the 8-10x suggested earlier. Canisters in general are more efficient than HOBs, good canisters are much more efficient than HOBs.
HTH
snookers
09-16-2003, 9:23 PM
thank for the helpful hints...
What about switching from HOB to cannister
in established tank, any precautions/guidelines...
?
Thanks again for the support.
-s-
If I am switching from one unit to another on an established tank, I just run them in parallel for several weeks ( min. 3, better 4 or more), then pull the old filter off. That is fairly standard and routine for me.
But I admit I do always have spare filters running somewhere in case of emergency- which have not so far been needed in routine trade-out of filters as you plan. Parallel operation seems to inoculate enough that the new one can take over without spikes. But moitor and control your feeding a few days until you confirm no ammonia or nitrite seen. I will also admit that most of my tanks are planted, and none are over-stocked.