Sand Reactor???

I was in a LFS for the first time on the other side of town. (Beautiful Coral Tanks). I noticed he was running his coral tanks on a giant sump, with the biggest U.V. I have ever seen and ozone. He also had a giant reactor, but he was running sand in it, He was very busy, and I never got a chance to ask him the purpose of that. i had never seen it before. I can't seem to find alot of info on this. Anyone know what this does???

 

Sounds like a fluidized bed filter. A media is kept in suspension to increase biological filtration. Big hazzard comes in the case of a power outage and can cause a massive tank crash as all the bacteria dies off.

 

could also be a diatomacceous (sp?) earth filter... some people use them! the stuff looks exactly like sand and has fluid running through it- traps very small particles and tends to work fairly well. They've been used on swimming pools for the longest time- I've never used one on my SW aquarium however, but they do sell them for SW aquariums!

 

It is a fludized sand filter like they already stated. I ran one on my tank for about 2 years with no problems. Took it off after the tank had matured and i needed the room for something else. Worked great for me, just make sure you have a good check valve on it.