How do you know if a canister filter will produce too much current for your tank? i have a 37 gallon tank and want to add a canister filter because I am under-filtered right now. I have heard great things about the Eheim Pro II 2026 (quiet, self-priming, EASY to maintain). It has a pump outflow of 250gph and filter outflow of 172 (which is just what I'm looking for). It's for tanks UP TO 92 gallons. So would that be too much current for a 37 gallon? I think the outflow is adjustable. But I don't want my goldies to be swirling around in there!!


Please advise soon as I need to get a new filter up and running ASAP!!

Thanks!!

I find my internal filters produce WAY more current that my 2 canisters. But what i do with the spraybars helps to decrease the amount of current, seeing as i need HEAPS of filtration on my tank.

I keep the glass lids on my tank at all times and point the spraybars to the top, that way it deadens out alot of the harsh current and gets a bit of aeration going. Just make sure its not going to leak out the top of your tank and leave you with an almighty mess

Seems to work well for me Oh and also i fill my tank to leave approx 2cm of room at the top, that way i can still aerate the water using the filters but its not REALLY noisy (you know how annoying splashing water is on the top of the tank ).

My canister has an adjustable flow rate - a spec you will want to ask for when shopping around. The spray bar is very gentle causing enough surface agitation (but I also have a bubble wall) but not a ;lot of current in the tank - far less than a powerhead and better than a power filter. I don't even have to use ornaments and plants to mitigate outflow and diminish currents.

I would get the bigger one as goldies need extra filtration, you may add fish, you might upgrade tank size, etc. For the investment, you want something versatile that will grow witrh your hobby. There is no such thing as`too much filtration - just make sure it is adjustable. I'd go for thr Pro! I love my Eheim!!!

Hope you find the right filter soon!

I would not worry too much. For the 37 gallon tank you need between 370 and 555 gph filtration. I always aim higher. At 170 gph, you need more than two of those cannisters to properly filter that tank.

As the others have said, the cannister comes with a spray bar that can be adjusted. I have spray bars pointing at the walls, one at the lid of the tank, and one that srays under another HOB filter and drops. One, in a bubble eye tank has an extra cover - much like a heater cover that is over the bar. It is about 3/4 inch larger in diameter than the spray bar - the water sprays out and then hits the cover and drips into the tank. It breaks the current very nicely without compromising the gph.

You can also break currents with stategically placed plants, rocks and other decorations. The fish like some current, as long as they also have places of still water to rest or sleep in. Many fish will dance in the bubble bars and swim against the currents by the hour - it is great exersize and seems to be a lot of fun!

Great!! I have 250 gph so far so I think adding another 170 should do the trick. I'm going to get it ordered today.

Thanks, everyone, for the quick responses!!