Calcium Precipitating out of solution?

[mrg02d]

Hello all,
I have some SeaChem Reef Complete that I added to my tank to raise calcium a bit. My calcium was at around 400ppm, so I added a 5mL of the Reef Complete. Once it hit the water, it appeared to have precipitated out the calcium? White particles instantly formed and floated all about. They are gone now, but just not sure if this is a bad thing?

My KH is 8dKH. I know it should be 9dKH at least. No idea why its low like that. (Measured before adding the calcium).

Should I worry? Should I add anything?

Matt

[neilanh]

Pretty common, but I don't think it's Ca that's causing it. When I dose Alk (2-part) it does that same exact thing.