Cupramine Dosing Question

[snake42490]

I know how to dose Cupramine, but everywhere I read says you need to test on a daily basis. This confuses me.. As long as after the second dose to get to .5 ppm couldn't I just make a little mark on my tank and top off the water to that line and no matter what it would be .5 ppm unless I were to physically remove it? Maybe I am missing the point! Can copper levels change over time?

Thanks

 

[MellowReefer]

The levels of cupramine in your tank should not change if you have no sand or rocks in there. I test once when I'm finished dosing it and sometimes after a few weeks and it's always the same. Like you said if you do a water change of course you will need to add that amount back in. The only thing that surprised me is when I think I've removed it all and it the test looks like zero (clear) I put in a new polyfilter and it turned light blue again (meaning there was still some cu in the water).