Beneficial / Biological Bacteria

[Reef Pets]

I am in the process of setting up a new system and was wondering if this might work. I have a 48" X 44" X 29: high container that I want to use as a refugium. But, I want to get the most out of the tank as possible. So, I wanted to put a medium sand bed at the bottom, live rock on top of the sand bed and then Chaeto to grow over the rock and sand. Basically three layers of filtration.
Once the Chaeto grows completely over the top of the rock then of course the live rock would not receive any light because the Chaeto grows so thick.
My question is does the beneficial bacteria (aerobic and anaerobic) need light to do its job of biological filtration? My other concern would be the final stage of the nitrogen cycle and the gasses being able to pass through the Chaeto to escape via the water surface.
I have never tried having live rock in complete darkness therefore I thought someone might have information on the subject?
Gary

 

[Sikryd]

That is what I do currently.
I can't grow chaeto to save my life though, so I don't get much blockage of light.
I have sponges and other things growing though too.
I would recommend swishing around the water and sucking it out every once in a while when doing a water change to get rid of the detritus that can get stuck in the rock and lay on the sand. I don't have much flow in there so it settles pretty easy - which is part of the goal.

 

[Reef Pets]

Sounds like I use to do what you have going now. It always worked well for me but I cut back the chaeto all of the time. I am just concerned about the chaeto covering the rock. If it is an issue then I can figure out some where else to put the chaeto, but I would rather not if possible.

 

[dfisch1]

You are basically making a cryptic fuge by blocking light with chato instead of the container. It should be no problem. I run a drip bar type of setup on my fuge so that it "rains water over the back of the fuge. You will have a large amount of gas exchange happening in your skimmer, drain line outlet area, and surface of the main tank.

 

[gilmour01]

having little to no light wont affect the bacteria at all. what will you be keeping as far as corals in this system?

 

[droblack]

I have LR rubble suspended in a colander in my dark sump. Suspending the LR helps to minimize detritus.

 

[Reef Pets]

Thanks for the information everyone. I did not think it would be an issue but thought I would see if I could get more insite.

This will be the prop/grow system. All together it will be about 600 gallons with roughly 1000 pounds of live rock. Typically I have a couple huntred colonies and a couple thousand frags at one time. Therefore the system will be loaded with coral but will have 8-10 fish in it. The fish will include, a couple wrasse's, yellow tangs and yellow eye kole tangs. I mainly keep the fish for clean up only.

The other surface amount for the gasses to escape will be 3 other tanks that are roughly 4' X 4', a 16 square foot area of surface water.
Gary