Water clarifying chemicals

[poppin_fresh]

Randy,
I just set up a 180g tank and added sand. Last time I did this I added some of that aquarium clearing stuff to get rid of the cloudyness. It worked really well and I didn't notice any ill affects from it last time, but I'm not really sure whats in it. Do you know whats in that stuff? Is it safe?

[Randy Holmes-Farley]

These products are usually polymers (very, very long skinny organic molecules like a rope) that attach to crud in the water and cause it to precipitate. I do not know the consequences of using such polymers in a reef aquarium, so I'd be cautious and wouldn't use them just to speed natural processes along. They may be fine for occasional use, but that may depend on the exact polymer used.