How bad is this idea

[MoshJosh]

Using my canister filter as a return pump from my sump??? So I have toyed with this idea before but this time using the canister has an advantage over a regular old return pump. . .

I want to use my Fluval evo 5 as a sump, but AOI compartment is too small for a big enough pump. . . it is not too small for the canister filter input.

Basically if I do it the way I am thinking I can use a bigger pump than would normally fit in the evo and still use the media chamber of the EVO (in tank media basket).

The AOI camber would hold filter pad for mechanical filtration, matrix for biological (plus live rock in sump), and the canister would hold carbon. . .

 

[Kodski]

I've seen this question asked many times. It will not work due to the fact that canister filters are not designed for head pressure. When the intake and output of a canister filter are at the same height, the head pressure in the canister filter equalizes. This is because the siphon pulling water into the canister creates a pressure that is equal to the water the pump pushes out. Force down is equal to force up essentially. Take away the pressure that the siphon creates and the pump in the canister filter wont have enough power to push the water up to the tank.

You're a lot better off going and buying a 5.5 gallon tank and using some aquamesh to create a cheap and easy bubble trap and using a regular return pump.

 

[MoshJosh]

I've seen this question asked many times. It will not work due to the fact that canister filters are not designed for head pressure. When the intake and output of a canister filter are at the same height, the head pressure in the canister filter equalizes. This is because the siphon pulling water into the canister creates a pressure that is equal to the water the pump pushes out. Force down is equal to force up essentially. Take away the pressure that the siphon creates and the pump in the canister filter wont have enough power to push the water up to the tank.

You're a lot better off going and buying a 5.5 gallon tank and using some aquamesh to create a cheap and easy bubble trap and using a regular return pump.

Thanks for the reply, think I will grab a 5.5gal as you suggested. Thanks.

 

[stevolough]

Thanks for the reply, think I will grab a 5.5gal as you suggested. Thanks.

And on top of that depending on your set up as the filter clogs it effects your flow rate and could cause your sump to overflow

 

[V A R I A N T]

And, be certain to design a way to prevent back siphon from the return line of the display to the 5.5g sump. Without it, the sump could overflow.