Ok, so another 7 days have passed, no calcium dose, and my calcium levels now hover at 500. Suffice to say I was overdosing my tank with calcium, of course following the directions on the bottle:mad2: I can't image using a test kit every two or three days to monitor and adjust CA levels. Too costly and tedius. I don't want to fudge it either. Way too costly. I think a nice CA monitor is my next purchase and will dose as required and not as per bottle instructions. :idea: