I have built a hang on fuge and at one end it has area that is 4"x4" and 15" deep (was going to be an over flow for return didnt work that way though). the fuge is about 6-7 gallons and is on my 29 gallon tank. It has a sand bed of about 4 inch in the main area,3" mirical mud 1" live sand. I was thinking of filling the one area on the side with sand but was wondering if there is such thing as to deep. is there any need for flow above it, I have a small red sea nano filter turning the water so it dosnt go stail do you think i should keep this there if i fill it with sand? What kind of substrait should i fill it with?
thank you very much
dave

make sure you check out the substrate podcast shows, there are two of them that will answer all of this for you.. and more.. :)

basically the sand should be less than 6" deep, more than that is wasteful and non productive, the type of substrate should be fine aragonite or equivalent

i believe the podcasts are Ep27 and Ep28
Substrate pt1 - 27
Substrate pt2 - 28

or what if i fill it with egg creat and black out the sides and try for a spounge filter, what do you think would be a better filter?

you mean for something like a dark fuge?

ic ic... i want a DSB too.. i need to add more sand.. its not deep enough right now

ic ic... i want a DSB too.. i need to add more sand.. its not deep enough right now
i just answered a how-to question about that on this weeks show.. :)

A little off-topic, but I was in my LFS today and saw pre-packaged commercial bags of "live sand." It appeared to have sand, aragonite, or such in a sealed bag with water and a small pocket of air. The store was busy, or I'd have talked to the owner about it. Is it just me or does it not seem like Nitrobacter and Nitrosomonas would tank within 48 hours of being air-sealed and sitting still and in the light?
I apologize if this has been covered.

Personally, I think pre-packaged "live sand" is a scam.

You are much better off buying the dry sand in a bag and getting a cup of sand from your LFS tanks to seed, or from a friend.

If you want great bacteria in your system, there's many better ways to get it than buying sand that costs 50x what it should.

ya a dark fuge. what kind of flow do you think i will need? in my old eclipes hood (ill never get one of them again horrible idea) there was a lot of spoung in the to filter tray,i never had a pad in it.it had lots of direct flow and the spoung was small bits but lots of it. i already have some cool tube spoung in mytank that i can try and seed it with.