Sand again

[VoodooChild]

Ok, so I've got 44 lbs of SeaChem aragonite on the bottom of the tank, ranging in particle size from 1 mm to 1 cm. I know that this doesn't exactly qualify for a sand bed, but I don't think that I'm that far off. If I throw a 1" layer of southdown or the like on top of the arogonite and then 5-10 lbs of live sand, how much will I benefit from the bacteria, in comparison to a true DSB? Thank you.

[Satchmo]

Eventually, the finer-grade stuff will work its way to the bottom of the bed. The grain size you describe (up to 1cm) is too large to reap the denitrification benefits of a DSB.

[OrionGirl]

Hard to say. The thing about the sand bed is that the small grains and the depth combine to provide areas with very little oxygen, allowing bacteria to break down nitrates. With larger grain size, it's hard to determine how much water flow will still exist.

[VoodooChild]

Thanks for the replies guys. Could I, perhaps, throw a refugium on there and just but 4" of sand in there? I know that it wouldn't have anywhere near the same effects that a full 30 gallon could, but wouldn't it help? And still provide a refuge for little organisms too I suppose...

[OrionGirl]

Yep, that will help. You'll need to colonize it with maintenance critters--I'd probably just get a handfull of bristleworms, personally.

[VoodooChild]

Sounds good, but I've never seen worms for sale. Should I just hope they come with my live rock? Otherwise, could I just throw two or three blue legged hermits in there? I was looking to get the small one (I can't remember the company that makes them for the life of me). Otherwise, I was reading how you guys use AquaClear 500's. Those things are a waterfall! How do you turn down the rate of flow? Thank you. On the same note, has anyone used the CPR Refugium's before? They're 12"19" long (small or medium) and 4" wide. I was thinking that I could take out my Millenium 2000 and put on of these babies in there.