Using a canister with LR as a filter.

[jvin85]

Newb Question.

In theory (let's use an eheim 2217 for this example) if you wanted to use a canister filter for SW, if you filled it with LR would it not be just as effective as placing LR in the aquarium itself?

Could this be a possible alternative to keeping LR in the aquarium itself?

[DeepSeaBeauti]

I dont think so, One of the main things you want to give live rock is light. With out that it will become dead rock.

[jvin85]

and thus my logic has failed... (unless i build LED's into my canister).

But technically speaking if someone designed a canister that had internal lights, and placed LR inside. In theory it would work as a filter?

[twitchy4821]

yes, the live rock will still house the beneficial bacterias that you need for the process of waste removal. but, the rock will not have live creatures in it more than likely. what you will have to watch out for is detritus buildup, which will become a nitrate factory if you do not clean out the canister every once in a while.

[somethingphishy]

adding live rock to a canister as the primary source of bio-filtration could be suffient if the tank size is small and the fish load is light

[jvin85]

Excuse my ignorance, but doesn't detrius get broken down completely by bacteria? Doesn't detrius build up regardless in an aquarium?

[somethingphishy]

yes detrius and nitrates will build up in an aquariums unless removed by mechanical fitration (skimmers/filter socks/vaccuming ur sand bed/water changes)...but adding LR to a canister will trap ditritus and increase overall nitrates unless care is taken to keep it clean...something very hard to do with-out diturbing the biological filter i believe you are trying to create

If you are planning to keep a reef...I would advise against it because it will be harder to remove undesirable nutrients from the tank..

[Sk8r]

One of the worst problems with that scenario, I suspect, is the speed with which water transits a cannister. Bacteria I suspect need time to do their thing, rather like a uv filter, which can't work well with fast-moving water, I suspect you'd need yet another pump to provide aeration. And getting 1 lb per gallon of rock into an Ehiem cannister.

[kzooreefer]

When I first set up my system I used a canister filter and was told to remove the ceramic bio material out of it as it will end up raising the nitrates in the tank. As live rock and ceramic serve the same purpose I would assume that you would not want to keep in a canister filter for the same reason.

People have put live rock in HOB filters and use them as mini refugiums as they do get some light.

[DeepSeaBeauti]

One of the other major benifits of "live rock" is to have all those critters that crawl around in the rock. Besides the bacteria, many of them consume detrius. But like everyone else has stated i dont think its practicle. Why not just use a small aquarium, and build it to be a refrigum? Will be much easier to maintain, and you can see all the critters doing there job in there. I stare at my refrigum just as much as my tank. Cool stuff going on down there.

[RegalAngel]

Originally Posted by jvin85

Newb Question.

In theory (let's use an eheim 2217 for this example) if you wanted to use a canister filter for SW, if you filled it with LR would it not be just as effective as placing LR in the aquarium itself?

Could this be a possible alternative to keeping LR in the aquarium itself?

What you want is a place for the bacteria to setup so they can do their job. Yes, this will work but I would try using something like Matrix (Seachem) or Pond Matrix to allow a better material to house these bacteria.

I have close to 40l of Pond matrix in 6" PVC tubes that have the flow from a pressure pump and they provide the "Live Rock" for the bacteria in my system.
No LR in the tank to give the fish more room to swim. I have a very large 125 sqft of filter canister upstream of the tubes that keeps the tubes "clean" and I use Seachem Stability bacteria for the they can thrive in aerobic and anaerobic environments.

http://bwclark.smugmug.com/Aquariums

[israel.kendall]

Originally Posted by DeepSeaBeauti

I dont think so, One of the main things you want to give live rock is light. With out that it will become dead rock.

What is your basis for this statement? From my understanding no light is needed to keep rock "live". All sorts of things live in LR without light. My HOB filter has rubble in it (without light) and there are tons of worms, sponges, pods, etc living in there. It's a miniature "cryptic zone" of sorts.

Lots of people even cycle their tanks without light to keep algae down. Doesn't this prove light is not needed?

[lordofthereef]

Originally Posted by DeepSeaBeauti

I dont think so, One of the main things you want to give live rock is light. With out that it will become dead rock.

With all due respect, this simply isn't true. The life (bacteria) on the rock needs no light to thrive. Certainly coralline and other algaes will die off without the presence of light, but that isn't what matters when we are talking filtration in terms of live rock.

All that said, to the OP, I think your idea would become more of a detritus trap over time.

[wmdick_2007]

It will work, however, if the water is not filtered before the rock the rock pores will fill up and the surface will collect waste. And no, about bacteria breaking down everything. Most organics yes, I would never need to clean my filter and change media if they did breakdown everything.

1. I use filter pads stacked, I cut myself from bulk. Then polyester fill, then carbon, then ceramic rings. The water needs to be clean before the carbon or ceramic rings so the pores stay open and the bacteria which take 20+ days to grow on the surface of the carbon can do their thing. The pores in the carbon and ceramic rings house anaerobic bacteria also.

My filters run 3-months before maintenance and all are on the return to the display from the sumps.

[DeepSeaBeauti]

I agree that the rock does not need to have light to keep critters alive in it. But if all your doing is using it because live rock usaly houses nitrate processing bacteria, and critters it seams like a waste. No light will kill off any of the coraline algae, which leaves me to ask why even bother using live rock in the first place. Just pack the canister with a media that the little guys can thrive in without threat of being eaten before there time.

[Frogmanx82]

I have done something similar to what the OP is suggesting. You can see it here http://reefcentral.com/forums/showthread.php?t=1959429 I went with 6 inches of sand rather than all rubble. The sand has no flow through it so it acts more like a large live rock. Live rock works because you get low flow low oxygen areas where the nitrates can break down. Small rubble in a high flow environment won't do that same job on nitrate. If you got a really big canister like the Fluval FX5 you may be able to put large enough rock in there to have those low oxygen areas. Also you can cut into the middle and upper chambers to divert flow from going all the way to the bottom of the filter which would help develop those low oxygen zones.

The guy who said rock in a canister would be dead is obviously dead wrong.