refugium deep sand bed

[ToriLoo]

I just built a sump with a refugium section in the center and want to put a deep sand bed in it to help reduce my nitrates. I only have a shallow sand bed in my 55g display. When I put the new sand in the sump I planned on seeding it with some of the live sand from my main tank. What I'm wondering tho is should I leave the sump separate for a month or so with the new sand seeded with the live sand from my main tank and let the bacteria colonize, or am I safe to start letting water flow thru the sump from and back to my main tank right after adding both sands? I guess what I'm worried about is the new sand not having the good bacteria established enough in the sump and causing a mini cycle, ammonia to nitrite to nitrate, or do I not have to worry about this? This is my first time trying a deep sand bed to reduce nitrates and I'd hate to do it wrong and wipe out my whole tank. Any help would be GREATLY appreciated. Also, should I have some sand sifters, snails and such is the sump, or is it better to leave the dsb in there undisturbed? I know that you don't want any oxygen in the lower layer of the sand, but didn't know if I should have something stirring up the upper layer. I'm thinking of adding about 6-8 inches. Once again, thank you for any help. Jay

 

[mylifeismyown66]

I have a DSB in my fuge (I think a DSB is considered 5"-6") and mine is about 5.5". I had mature sand in my tank that was also quite deep, maybe 3" or 4" in some places and in my new DSB in the fuge I had a few inches of mature sand that I had in a past smaller fuge along with a good amount of brand new sand. I ran into no issues doing this, but maybe someone else can shed some light on this subject.

 

[kevinpratt823]

You really only get a "cycle" from live rock/sand that is left out long enough to have die off. If you are adding new dry sand and seeding it, it should not be a problem. Actually you're probably better off running it, as I would think it would colonize quicker, and maybe put a piece of established live rock in there also. I use the "mineral mud" from CarribSea in my fug's, covered with a layer of reg sand. This stuff seems pretty good, as it can take a long time for the denitrifying bacteria to colonize deep under the sand.

 

[JayM]

Adding a DSB created with well-rinsed sand, and seeded with sand from your existing system shouldn't cause any cycle. Setting it up as a remote sand bed in your fuge will give you options if it has issues as well. I run a DSB as a separate 40G breeder in my system. I added some rock to the top, and all kinds of pods, sponges, etc grow there.