My canister filter with lots of life

[Rythic]

Ok so I went to clean my canister filter which has a pound of live rock rubble in the bottom tray then filter media in the top tray. It's been about a month since I've cleaned it and well sand was building up at the bottom about an inch maybe a touch more. When I lifted up the tray containing the live rock and exposed the sand bed it was full of life all kinds of little critters in there and lots of copepods. So I was wondering if I should just take out the top tray and put more rubble in there or should I just leave it the way it is? SHould I take out the bottom tray and leave the live rock on the actual sand bed? When I saw the critters, I just filled it back up with water from my tank and cleaned the pollyfil and put everything back the way it was. I know most people dont like canisters but I've haven't had any water parameter issues.

 

[DaveK]

If I were using a canister filter, I would not place any rubble rock or similar material in it. As you can see it becomes a real trap. This is exactly what you don't want. Put the rubble rock in your tank. Use the canister filter for mechanical filtration and chemical filtration only. Be sure to clean it often, about once a week.

As to why rubble rock and similar material is bad, suppose you had a power failure. In that case, all the living stuff in the canister would die quickly. Then when the power comes back on, you flush a lot of dead material and stuff into your main tank.

 

[schriss]

I have the same setup, big eheim 2078 canister half filled with rocks. But I have it hooked up to battery backup supply. I've been running rocks in canisters for 2 years now, never actually take rocks off. I just shake the canister sometimes or put it to max flow mode (its electronic, can change flow rate)