Trying to treat a 37 gal
. fish-only tank for ich. 1 Yellow Tang, 1 Royal Gramma, 2 Firefish, 1 Perc, and a Shrimp Goby.
Ich appeared shortly after I added the Tang. (He was intended as the last fish.) I lowered SG
to 1.009, but the ich came back in the third week.
I treated with Marine Enterprises International copper sulfate, monitoring with test kit from same mfr. Instructions say 1 drop per gal
., but there's a good bit of crushed coral, and I figure that's why I had to add a ton of copper to get the levels up.
Kept the copper between .15-.3ppm for 17+ days after the last ich spot disappeared, and then put carbon back in. Did a water change two days later, and then two more days later I saw the first spot again. Ich is back.
Copper still read .15ppm, so I put just a few more drops in, waited a three days and added some more, and then again three days later. Yet each morning I see ich again briefly.
Marine Enterprises now reading solidly above .3ppm! Bought a Salifert kit -- it's a lot harder to read, but it suggests I'm in the vicinity of .25ppm. Today the spots are on the Gramma. Yesterday they were on the perc.
Haven't lost any fish to the ich, but I'm starting to worry about losing fish to the copper. The tang's clamping a little, and he's got some blood streaks, but his appetite's fine.
How much copper can the fish tolerate? How high / how long do I copper to cure the tank? Is there a better test kit? Can ich become "resistant" to copper?
What does the presence of crushed coral do -- does it simply leach copper out of the water, or is the effect more complicated than that? The Marine Enterprises kit reaches peak levels in the first minute or so. The Salifert kit (drops, not powder) reacts within the normal 10-minute time, and does not get any darker with additional time. I assume this means my copper is not "bound" in any way.
I've been led
to believe that the life cycle truly can be broken; that ich can be totally eradicated from a tank. Yet I see posts in forums where experienced fish-keepers have been forced to leave tanks farrow for a month or more because nothing else works.
I know this thing has a life cycle, and that spots on the fish do not indicate low copper unless they persist. How long should it take after an effective dose for the fish to start appearing spot-free?
If I have to, I'll let the tank go farrow. But I'd much rather megadose the copper than simply destroying these fish.