Since it's pool chemicals, it's probably calcium chloride. As I understand it, calcium chloride is what's in things like Kent Turbo Calcium that raise calcium without changing alkalinity. Since the pool version is very concentrated, it is probably much more exothermic than the usual additives sold for aquariums. You can get nasty chemical burns if you're not careful.
Pls be carefull when adding none Aquatic rated products into your prized aquariums (I am not condoning this).
I have been testing this stuff for sometime now with great success. I gave some to Todd to lift his Ca up, he was having problems keeping it up (mind the pun).
Yes it is Calcium Chloride and yes its very strong (twice that of Kent Turbo Calcium). There are other chemicals in there also that add value to the aquarist.
Again, I am an experienced aquarist and did my research before attempting this. I spoke with several reef geeks and chemists and cross referenced all MSDS literature I could find.
I am at this moment really impressed with the results. Coral growth has been absolutely spectacular. So fast I am loosing corals because I didn't frag back enough in time. See picture of Coral fusion.
Green Bali Slimmer an Inch a week and its as thick as my fingers. Multiple branches just popping out of everywhere. Coral color is retained if not intensified.
Can anyone source this stuff. The answer is no. I've personally looked around. I have a local supply company who gets it for me. I just ordered the last 16x 5lb containers worth. Thats all they had.
Normally it comes in 5lbs and 15lbs.
Again like everything there are risk. There has been no long term study on this chemical and dosages are simply a matter of opinion or suggestion. I would not recommend this to just anyone. Well not anyone I like.
Note: Coral growth is not the only sign of a happy aquarium. I really do maintain my tanks well and there could be other factors at play.