Yet another question

[Marvin]

Ok, i have had my 37g tank for about 3 weeks now. I only have about 15lbs of live rock and 10lbs of crushed coral. I just read some info on live sand @ TBS.

How important is live sand or some of the home depot sand i have been reading about?

Thanks in advance.

[Gealcath]

Sand has more surface area for bacteria to colonize, and the purpose of a DSB is to remove nitrate, which requires low oxygen. The large grain size of crushed coral doesnt work for the low oxygen loving bacteria to break down nitrate. Also you could say fit 100 sand grains into 1 piece of crushed coral, which is essentially 100x the amount of bacteria compare to 1 peice of crushed coral. A good 3" sand bed is having the surface area of about 4 achres of bacteria in your aquarium.

[mogurnda]

The other problem with crushed coral is that it traps a lot more debris than the finer sand. Ultimately, the CC bed will become a source of nitrate, rather than helping to eliminate it like finer sand.

[Marvin]

Is there a way for me to still add sand to the tank?

[Gealcath]

One thing you can do is just remove the crushed coral if its already in there, place into something like a Nylon, then replace the crushed coral with Sand, and then put the Nylons with the crushed coral into the aquarium (so the bacteria in the coral can colonize the sand), and then after 2 weeks or so remove the crushed coral and the nylons.


One thing i did was scooped out the crushed coral (since it has partially aragonite sand), then put play sand into the aquarium, and the mixed in some of the crushed coral and aragonite sand into the play sand. Then 3 weeks later i used a net to filter out the sand and the big parts (the sand falls through the holes in the net, while the coral stays in the net)

[Marvin]

Ah Thanks!