Could had been sand. My yellow tang did that a lot
So let's move forward......
What is going to be critical now is maintaining therapeutic levels of copper. You'll need to test frequently to make sure you're maintaining these levels. Dependent on the type of copper, you'll need to have a test kit to measure that type of copper. Seachem and Salifert test kits are for ionic copper (such as Cupramine), while API tests for chelated copper (such as Coppersafe). You can not use an ionic test kit for chelated copper, and vice versa. Note that the therapeutic level needed differs from each product....so take note of the instructions on the bottle of copper you're using. Example is Cupramine requires 0.35 - 0.5 ppm while Coppersafe requires copper levels of 1.5 - 2.0 ppm. If your copper level drops below these levels, you'll need to start the clock all over again. You'll want to maintain copper for 30 days. Do not add any other additives to your tank.....especially ammonia reducing products like Prime.....this turns copper into a very toxic compound that will kill your fish. If you had cheato or any other algaes in your sump, at this point, throw it out....the copper will kill it. If you have carbon, take it off line.
Now, as far a white spots dissappearing....don't be fooled. It could simply be the parasite has passed into the next stage and has dropped off the fish. Doesn't mean your "done."
Best of luck.....and ask questions.
Just re set up my old bio cube. Put the snails and crabs in there for the time being. Figured I can keep it going as a quarantine tank.
Its small but better then having nothing.
Sent from my iPhone using Tapatalk
How many gallons is your display tank and what's the fish count now?