Yesterday marked the day that the block was fully dissolved.

Tossed it in on 02/06/2012
Fully dissolved on 02/28/2012

Looks like I'm in for 2 blocks a month to keep my calcium levels up.

I'm sorry but I have not tested anything other than calcium and PH.

Since calcium stayed between 550 and 620 I'm going to move them from the intake section of the sump and place in the return section where there is less flow and hopefully I can get calcium to stay around 500, I would like 440. The intake also had low flow since I don't run water through the sump very fast.

So far I'm happy and will continue to use them.

I have noticed stable PH, high calcium, great color on the SPS and faster SPS growth since using the block.

I have nothing negative to post at this point...maybe price but $50 a month to keep calcium up is not that bad.