Cody

im thinking about getting a cansiter filter, i have been looking at them, but what confuses me is that, i see a one thats rated for 80 gallons, but only has 185 gph, and my bio wheel 350, which is rated for a 75 gallon has 350gph, so is the rating or the gph more important

Randall

I cannot figure out where the manufactures get their GPH ratings from.
Cannister filters move more water than a HOB.I think it is always a good idea to overfilter any tank.What size tank do you have?Ideally you want to filter all the water in your tank at least 5 times an hour.

clinton1621

Canister filters have a higher rating for gallon size versus gph because they are more efficient at cleaning the waste out without 'flowback' like a hang on filter. So the gph as far as for filtration isnt relevant as much with a canister... I still like to use a hang on or bubble wall with a canister though for extra circulation and aeration, as canisters have no direct oxygen contact like a hang on does, they go soley off of dissolved oxygen in the water.

sirdarksol

Canister filters do a more efficient job of filtering water, so a canister with a lower GPH can actually filter better than a HOB with a higher GPH. This is because canisters force the water through the media.
As far as where they get their ratings from, it's simply how much water gets sucked in and spit back out in an hour. They should be fairly accurate. If it's not, then that company actually lies about their product, which is illegal if it's taken too far. (There will be variations, of course, but they should be within a certain range)

rifter098

with a canister, u dont need as much gph...idk why lol, but i am positive that it isnt needed...the rating is reliable, but i like to over filter my tanks just in case something goes wrong...with a hob, most people recommend that the gph should be 10x the gallonage of the tank...but with canisters, i think its like 3-5x the gallonage

Cody

its a 55 gallon i have to hobs, one for rated for 60 gallons, and then biowheel for a 55 gallon which as 200-250 gph, that run on there, but im thinking about getting a cansiter for it, i want something thats not tooo expensive but its still a nice filter and not super loud, and recomendations, if you think about it a filter with lower gph, is most likly filtering the water better, but slower