yes, you want to raise the copper level slowly over time. Adding it in all at once could be what did it.
From Humblefish's guide to copper:
How To Treat - First, it is important to know what kind of copper you are using.
Cupramine is fully charged (ionic) copper, and has a therapeutic range of 0.4-0.5 mg/L or ppm. You would use a Seachem or Salifert copper test kit for Cupramine, as those are capable of reading copper in the low range.
Copper Power, on the other hand, is chelated copper. It has a much higher therapeutic range of 1.5-2.0 mg/L or ppm. As such, you need a “total copper test kit” such as API.
In addition to the aforementioned hobbyist grade test kits, the Hanna High Range Copper Colorimeter (HI702) is
capable of reading all forms of copper. More info on that and other applicable copper test kits here:
https://www.reef2reef.com/threads/copper-test-kits.257924/
Standard copper treatment lasts 30 consecutive days. The reason it takes so long is copper only targets the “free swimming stage” (the same holds true for
all chemical treatments &
hypo). While 7-14 days is the “norm” to reach this stage, certain strains of ich have a prolonged life cycle. Indeed, even 30 days may not be sufficient in some rare cases. This is why it is so important to observe after treatment ends, to ensure symptoms do not return.
A therapeutic level
must be maintained at all times during the 30 days, so testing often is important. If the level drops even slightly out of range, then the 30 day clock restarts. One reason your copper level may drop unexpectedly is if you are treating in a tank with rock and substrate; these should be avoided with copper due to absorption. Conversely, if you exceed the therapeutic range you risk killing the fish.
Copper is a poison, pure and simple. It only works because most fish are able to withstand being in it longer than the parasites. Knowing this, it is wise to raise your copper level very slowly (over 5-7 days) instead of the usual 24-48 hour label directions. Doing so increases your odds of successfully treating a “copper sensitive” fish. The one exception to this rule is if
Marine Velvet Disease is suspected. Due to it's fast killing nature you would want to raise the copper level to therapeutic within 24-48 hours when treating for velvet. Remove copper after 30 days by doing a large water change and using a Poly Filter, Cuprisorb, etc.
