Welcome to R2R! Most suggest copper for 30 days. Then remove copper or transfer to a clean qt for observation.
Here's the suggested treatment with copper from our own Humblefish. Hope this helps.
Copper: Treats Ich (Cryptocaryon irritans), Marine Velvet disease (Amyloodinium); possibly Uronema marinum
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 0.35-0.5 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. Coppersafe, 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’s to measure Coppersafe.
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 allchemical treatments & hypo). While 7-14 days is the “norm” to reach this stage, certain strains of ich have prolonged life cycles. Indeed, even 30 days may not be long enough in some rare cases. This is why it is so important to observe after treatment ends, to ensure symptoms do not return.
Therapeutic copper levels 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 starts all over again. One reason your copper level may drop unexpectedly is if you are treating in a tank with rock and substrate; those should not be used in the presence of 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 3-5 days) instead of the usual 24-48 hours recommended on the labels. Doing so increases your odds of successfully treating a “copper sensitive” fish. Remove copper after 30 days by running activated carbon.
Pros - Readily available
Cons/Side Effects - Appetite suppression is a common side effect. If a fish stops eating, don’t add more copper until he resumes. If the fish is still not eating after 2-3 days, start doing water changes (lowering the copper concentration) until he eats. If this happens a second time after you resume raising the copper, you’ll know you’ve encountered a “copper sensitive” fish and an alternative treatment should be used instead. Some species of fish, such as angels, puffers, lions and mandarins are notoriously difficult to treat with copper.
