jprime84

38 gallon tank, and I have 250gph right now. Should I increase that if I plan on being slightly high population? In my mind it seems like I wouldnt if the tank water is theoretically being cycled 6.5 times per hour.

mathas

That depends on the type of filter.

A hang-on-back filter, for example, is less efficient than a canister filter... the water can bypass the media more easily, and the intake is almost directly under the return, meaning you're recycling "clean" water far moreso than you would with a canister filter.

Common guidelines I've heard are that you should shoot for 9-10x turnover with a HOB filter, and 4-5x turnover with a canister filter.

Shawnie

also depends on what you plan on stocking....lower waste producers might be ok

jprime84

I would only like to add 3 bosemani rainbows to my current fish. The filters are HOB filters. I was hesitant to think about canister filters because I was afraid the plant matter in my tank would clog them too frequently. When you say 9x turnover, does that mean cycle the capacity of the tank 9 times per hour?

Shawnie

IMO HOB are way worse for my plants but I only have anubias , moss, and ferns....im always digging them out of the intake...

Nutter

Turn over isn't as important as media volume when it comes to biological filtration. The efficiency of a filter also depends on how easy it is for the water to bypass the media inside. IMO canister filters are far superior to HOB's when it comes to planted tanks. If you want to replace your current filter with a cansiter then you can just use a foam pre-filter placed over the filters pick up if you are worried about plant matter getting sucked up. I use canisters on my planted tanks & don't have any trouble with that though. You will find that because you need less of a turnover rate with canisters that they have less suction at the pickup so they get less debris. Canister design also has the water being pulled through the media before it ever reaches the pump so all but the very smallest of debris will be removed already.

The short version of that is that if you want to have a heavily stocked tank, then get a canister filter & don't worry about the debris. It will be a non-issue. Try an Ehiem 2213. They are what I use on my planted tanks, (2 x 2213's on each 250lt tank), & I never have any problems.