2 filters?

[oqs]

I'm going off to NA to get another filter for my 3' tank. i have a Eheim 2213 now which i feel isn't enough for the tank. so after i get the new filter, should i run it independently or should i run it in series to the 2213? how do i run it in series? connect the input of the new filter to the output of the 2213? leave both filters switched on?

[loupgarou]

run it independent. that way you get more oxygen and food (ie: nutrient rich water) for the bio filter to process.

[lsz]

i am running 2x2217 in series
my girlfriend is running a 2217 and a 2228 in series.

the advantage is that you can have one filter as purely mechanical, the other biological. the capacity is massive.

some points
(1) yes the Outlet of filter #1 is connected filter #2. if hose sizes are different, you need to find some adaptors. If not, just straight from one to another.

(2) you only on the 2nd filter in the series. Do not on both. it is dangerous. Canisters are not designed to work with pressurised inputs. Will leak/burst.
FOr the first filter, take out all the impeller etc to minimise resistence.

(3) you need 3 sets of valves if you using classic series...
1st set is at inlet to the series
2nd set is at the hose joining the 2 filters
3rd set is at the outlet of the series.

(4) only the first filter (mech) need to be maintained regularly. Disconnect it via the 1st and 2nd valves.

(5) you have to do everything to "salvage" the flowrate because flow will definitely reduce a little when passing thru 2 filters.
If you have 2 fitlers of diff power, use the more powerful one as the 2nd in series, and use its motor power.
Other than that, minimise all elbows etc etc that will affect flowrate.
Minimise the lenght of the Output hose..this is where a lot of flowrate is sapped.
YOu can have the inlet hose longer because water flows thru inlet via pressure difference and gravity rather than filter power itself.

SO, your inlet side (the J tube) should be at the far end of the tank away from the canister. the output side should be at the side of the tank near the canister.so you can have both good overall circulation and minimal power loss