here's a handy chart
You can find your filter and compare it to other brands with a similar GPH and see the difference in recommended tank size. There's a big swing between some.
I'm having trouble now with a filter that I want to buy,here, because it doesn't tell me the recommended tank size. And 290gph is equivalent to an Eheim for ~160gallon tank or a Rena XP1 for a ~45 gallon tank.
Confusing at best, right?


