So I am confused about how to dose seachem's cupramine after a water change. The number of drop thing confuses me enough. I typically am doing 50% water changes (5 gallons) every other day during treatment. So how many drops do I need to add back into the tank after the new 5 gallons is in? Or even more helpful....how many ml, tsp. etc....? It took me forever to get the right .5ppm reading....now when i do a water change I am worried I won't be able to know how much to add to get that reading again....help!