Live Rock Rubble in Canister (same as live rock in tank?)

[fantastic4]

Hello my fellow reefers!

Ok, why is this a bad idea? I think it makes sense, however, so many people state nitrate factory.

Currently running canister filters filled to the rim with live rock rubble, big and small size rubble, packed tightly. In theory the flow through the rubble would equivelent to live rock filtration with constant water movement. Seems like a good idea to me, adds live rock surface area to tank volume if tank live rock is full.

Has anyone run this method and ran tests on the water quality with and without this technique?

 

[dendro982]

Not doing that, but keeping a lot of LR in the sump, same idea.

What I see in it, is that:
- if you rock is after mechanical filtration, it should not become the nitrate factory,
- but for denitrification better to have slow flow, like 40-50 ghp and low oxygen environment, or the rock, much larger than rubble.
Just a thought.

 

[crispyreef]

The big problem about canister filters is that detritus builds up in them and is not removed. Canisters must be cleaned out often to avoid problems.

 

[ryan_paskadi]

really all you need is something that has a lot of surface area that bacteria can attach too.....LR is a waste of money IMO and cannot be cleaned or replaced easily. I suggust oyster shells.

 

[FishAreFriends2]

Im doing the samething, I have spare rock laying around and didnt have any more room in my tank. I didnt want to sell em or toss them in the backyard to dry'em out. So I took my canister and emptied it and tossed my spare rocks in there.

 

[happyface888]

Hey Im on the same boat, I have a fluval 304 canister and I got alot of extra rock after a down grade before and didnt want it to go to waste so I am going to stick it in the canister.

 

[Bri Guy]

JMO, but I think the extra bio-area and water would be good. A pre filter would help not clog the rock so much. And again JMO but if larger rubble pieces were used and you lower the flow through the canister, I would think that it would host some anaerobic bacteria and get rid of some nitrate, not add it.

I think this is an excellent idea for small nano tanks w/o sumps, but for larger tanks, sumps/fuges are the way to go.

 

[Crazy4salth2o]

I would jest clean out the canister every couple of months to avoid a build up of anything. I have a frag system and keep all LR in a 50 gallon vessel. working just fine. Not sure why the nitrate issue is coming up. any media that get clogged with detritus is a nitrate factory.

 

[FUA]

I have the same kind of idea, a lot of rubble in a section in my sump that receives slow flow. seems to be working for now but tank is still young.

 

[K' Family Reef]

i filled my canister full of LR rubble over 6 mos
(in a 30gal softie) ago and havent opened it or cleaned it since... after reading another thread about this a few weeks ago i decided to test the water (hadnt been tested in that long either)... the nitrates much to my surprise (espec based on all the bad publicity about this) were either not detectable or barely measurable using saifert test kit... my phosp were a little high but still below .05... the only other filtration i have in this tank is a hob filter/skimmer combi (w/ more LR rubble inside) that is about as worthless as they come.

 

[madadi]

live rock in the main system is a good filter because its large enough to house denitrificating bacteria. on the outside of the rock you have aerobic bacteria and on the inside, deep inside, you have denitrificating anaerobic bacteria because they need an oxygen free environment.

if you have a deep sand bed and live rock, in my opinion, live rock in a canister filter has potential for more harm then good. keep in mind that the aerobic bacteria eat OXYGEN and NITRITE to release NITRATE.

so the live rock in the canister filter, specially if its small, wont help with nitrate, which usually systems have a problem with, BUT will help with nitrite, which cycled tanks don't have a problem with, AND eat oxygen which your fish need.

more and more folks using stop using bio-balls recently because they produce nitrates it seems. a canister filter is worse then bio-balls because it eats up oxygen from the tank, bio-balls at least eat up oxygen from the air, thats why they are designed as wet/dry and the balls are not completely submerged under the water line. just my two cents, it does cause more problems then not. lower oxygen saturation over night, for example, which might contribute to lower pH overnight as well. if you must use rock rubble in a canister make sure its AT LEAST baseball size.