Sorry not sure if this thread goes here. But I have a canister and I wonder is it possible to take out all the trays and put live rocks and sand as a filtration system?? And is light required for rocks and sand? I am not going to add any Cheato.
No light needed. It's the bacteria in the rock that you want, and they don't need light. I keep some live rock in my sumps as a place for pods and to also kill off nuisance algae. Depending on the flow, I don't know if sand is a good idea, as it might not stay in the canister. I would also imagine that you're going to have to clean the canister out regularly as the rock will trap debris.
What type of canister is it? I also probably would not recommend doing this. Maybe if it was a 5 gallon tank or something it might make sense, but the extra amount of sand and rock you would be able to put into the filter wouldn't be that much. Might as well just put it into the tank. Also I'd be worried about sand clogging the line out from the canister to the tank. Or damaging the unit in some way. Using the canister in the way it was designed should offer good filtration if your tank has the LR and LS in it.
Im still using my canister filter for added flow and plus i didnt want it to go to waste. I took out all the media and filled it up with live rubble rocks. And with out the foam pad, carbon and bio balls you dont have to do much maintenence if any.
I've been experimenting with this setup myself (rena xp3) filled all 3 trays with rubble but, I do have one sponge on the very top (to keep sand and excess rock from going through the unit). So far I'm finding some success but, it has only been running for 2 months now. Guess I'll have to see about long term success though.
I had it for 3 years now ever since I converted from freshwater. No pad or bio balls so it wont turn in to a nitrate factory. Never had to clean the rocks, but i did open it up just to check it out a couple of times. I have ton of pods in there even little shrimps. I also have a fuge with chaeto and more LR and a asm G1X skimmer. My nitrates is always less than ppm 5 and ammonia is less than .25ppm.