Don't know

[ThaDon]

So I am in need of a bigger refugium and I also have a extra 55gallon drum. I am thinking about making it my new refugium. About 6 inches of sand some rock, it will give me the size I am looking for. What I want to know is can you have a refugium that is to big/over kill. The drum will not b full to the top may be half way or so like 30 gal. Let me know what you think. I am also trying to add more sand to the system do to my ssb in the DT. The refugium I have now is around 12x12x12 I think it's way to small for a 165 reef

[Wall_Tank]

Anything that can hold water will work.  How do you plan to plumb the drum into your system?

[ThaDon]

I don't really know yet. Thinking a low flow gravity feed line in to the sump at the beginning and a pump at the middle for the return. My closet is now apart of my tank so I can have it in ther with my water drum for mixing and ro unit. Have the drain line back to the sump with a valve on it to control the flow so that it keeps water in the drum but at the same time don't allow it to over flow.  I will have the drain just above the sand but not to low to allow sand to be sucked down the line. The return at the top of the drum at water level so if power goes out it won't over flow the sump and a check valve on the drain side.

[Wall_Tank]

I would avoid the check valve.....make sure you can handle all of the water drain back.  The check valve will fail at some point.

[ThaDon]

Even a ball check valve

[ThaDon]

I will jput the drain line just below water level so it wont drain all water only a lital and forget about the check valve

[Wall_Tank]

That is a better plan.

[ThaDon]

So I got the drum cut around 35 gallon mark. I got about 4. -5 inches of sand and the bulkheads installed. I need to know if I can add old rock to it or should I cure the rock first or add a pice at a time over several months. Also what kind of light should I use.

[Wall_Tank]

How clean is the old rock.   If it is fairly clean you should be able to add it one piece at a time.......if it is dirty, or you want to be safe.   cure it first. 

Light is optional, are you planning to grown macro algae?    You can just get a compact fluorescent flood light if you want.

[ThaDon]

I have no way to cure the rock. The rock has bin dead for over a year and I had it in ro water for a few weeks and now it's out and bin out for a few weeks is that clean? How can I make shur that it is clean