Canister UNDER tank?

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Aquarium Advice FINatic
Aug 12, 2004
I have a fluval 204 that I would like to use for my 29 gallon tank. But when I read the directions, it says to place it on the floor near the tank. I would like to put it in the stand under the tank.

I think that people usually put the filter under the tank. Any reason why I shouldn't?

As long as the minimum distance is met between the top of the filter and the waterline. I have my XP3 under my tank in the stand, and it's perfectly fine. Doesn't need to be exactly on the floor.
...i dont see why u wouldnt if u could..

less travel for the water if it is right under the tank, dont have a chance of hittin it on accident and breaking something..
Oh. Is that their reasoning? So I guess if the hoses are long enough (not cut past the 'do not cut' line) I should be ok?

Much appreciated!
The reason for the minimum distance is so the cannister will properly prime itself prior to turning it on. The distance between the top of the cannister and the water level should be more than the minimum distance for proper operation. Basically, priming is filling the cannister and getting water to the impeller unit, so it's not spinning in a pocket of air. Check what your instruction manual says for minimum distance, and see if it meets that. I'm sure it will. I've ordered an XP2 for my new 29G, which will sit in the stand under the tank. Distance is fine. :)

Example: If the minimum distance is 25 inches, then the distance from the top of the cannister and the waterline should be greater than 25 inches. It's height that counts, not distance away from the tank.
I will check when I get home tonite. I wouldn't want to ruin my $3 filter. I have to purchase a few parts, but not bad, hey?!
Priming is simple, just pour water into the output hose until you clear most of the air out of the system. Works much easier than using the primer pump.
the distance is also for the output... the pump is only designed to pump water up so high...
Most will have both a min and a max height. If it was placed in a basment some 8-9 feet lower, the filter would have no problem priming the intake but might no be able to pump it all the way back up. Inside the stand will work fine...
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