Has anyone here ever used Tropic Marin bio-calcium?The LFS gave me some,so i figured i'd try it.It is unlike any calcium additive i've used.It is supposed to have CO2 in it as well as the calcium.It is in a solid form,the directions say to sprinkle it over the surface of the aquarium.I'm not sure i like this stuff floating around and settling on corals but they dont seem to be negatively affected.At this point,I'll try anything because i'm having trouble keeping calc/alk levels up.Looks like i have to keep testing.