DSB for the refugium

I am setting up a 120 gal reef tank and using the live rock and sand from my old 65 gal tank. I had a 2" sand bed. I received an email from the manufacturer of the Sealife Systems RM300 Refugium/sump. The refugium is a good size at 15"Lx12"Dx12"H. He recommended that I build a DSB (Deep Sand Bed) 6" high with live rock in the refugium. OK:-/ So what's the best way to do this? The live sand in my tank has some telltale algae growing underneath. A fellow reefer said I should give the sand a quick rinse with saltwater. I can do that. My thinking here is using more of that sand in the refugium maybe the bottom 4" and then adding fresh live sand to the top 2". Then mixing fresh live sand with what's leftover in the main tank and only having a 1/2" - 1" substrate. I could also minimize on the live sand from my old tank as I will be selling it later as a reef and maybe spare my new tank many impurities. The question is: How much sand do I need to keep the new tank from cycling with my stock in it? Anyone have any ideas for me?:-/

 

That seems like a lot of work to me. Why would you rinse your sand? What kind of algae have you got growing in it?

As for the dsb in the refugium, I would just buy new "dead" sand and seed it with a cup of live sand from the main tank.

 

Thank you for the reply. That is probably the way to go as it will all be live sand in no time. Take a look at the attached pictures of the sand I have. Question: How much of the old sand would you put in the new tank?

 

I would start with all new sand in the new tank and seed it with a cup of your existing sand but I'm the type that's too lazy to rinse sand

 

I like your approach! I think I should have a smaller substrate with the new tank rather than the 2" I have in my old tank. Most reefers I talk to either go the DSB or 1/2" - 1". I plan on using egg crate for under the rocks to protect the glass bottom from an avalanche. I will put the live rock in first so I can see what I'm doing and then carefully put in the sand in front of the rocks and move the sand into the rocks with my fingers. My Yellow Watchman and Diamond Goby will be freaked out because they are used to having 2" of sand to burrow tunnels under the rocks. I've already had an avalanche that killed two fish that were sleeping between the rocks. Oh well, you can't please all of them. Since I'm selling my old tank the new owner will have a nicely cycled tank to startup easily. Everybody will be happy! I'm going to need a ton of sand. Any idea how many lbs I need? 120 gal tank 48"x24", refugium 15'x12". I will use the best fine sand (Aragonite) I can find.

 

I think that there's a sand bed calculator on this site that could help you figure out how much sand you need?

 

Thanks, that calculator was great!