The first part of my response was no. You do not hypo salinate your dt. You do not treat or medicate your dt. You remove all your fish, and only fish and run the dt fallow for 6-8 weeks which would kill the parasite since it can not live without a fish to host on. You only treat your fish in a hospital tank not in the dt.
If you do not have the ability to run a hospital tank my suggestion is to treat your food with garlic and not do anything to your tank that may cause stress. This may or may not help and will not kill the ich parasite, but will help to bolster the immune system of your fish to help keep it at bay.
Thanks I left the link to read in my last post. Lee was several forums up to a year and half but his specialty as a Marine Tech was this subject. It's a good, clear, easily understandable read on Marine Ick.
I can be from new fish, inverts, rocks if its within its life cycle. It can jump from one thing to other in your current system it's a very evasive parasite. This was the reason the one of the threads was talking about a Hospital Tank where you could treat the infected fish and parent the spread of new parasites.
yes, it does come off, the form you actually "see" is usually only on your fish visible for a week, then falls off and starts the cycle again. Basically, unless you are only going to QT EVERYTHING you ever add to your tank, corals, inverts, chaeto etc, keeping ich out of your tank is dang near impossible. So the answer is, to keep it at bay. You do that by, feeding a wide varied healthy diet using garlic and selcon sparingly, unless during an attack. Keep stocking levels healthy and low, IMO that fish gets too big for your 125 and is prob one of the most ich prone fish out there(prob 95% of ich threads are because of a tang, and usually that one, a YT, or a Naso), but I digress, jsut keep feeding it well and read up on hopsital tanks, they are cheap to set up, but a PITA to keep params stable. I'd suggest starting a mechanical filter on your DT to use for a future QT/hopsital set up. It allows ya to grow some good bacteria to help keep params stable in a hospital tank after ya switch the filter over, I just use an old filter, add rubble to it and then have it to transfer over if needed. Thankfully, I've never had too.
Not sure what the rules are for posting a link to another reef site, sorry and feel free to delete, but this is an old ich thread I created that has alot of good info ICH 101 For the Noob by a Noob
I know it seems very confusing try to look at ick from its Life Cycle and how it host, then look at how to prevent and solve. When Lee was explaining it to me I printed out that article and highlighted what I just told you then I could see the order.
For now a health feeding and regular water changes can redirect the stress but will not get rid of the ick in the tank.
Once ich is in your system, IT ALWAYS IS, unless you leave the tank fishless for 6-8 weeks. It can't live on inverts, corals etc, only fish. But its no big deal if you practice good tank husbandry. It can come and go as flare ups, but its always there without a very strict QT regime.
Unless you started off with a QT tank or Hospital Tank and put everything through it it's nearly impossible later on down the line unless you start from the beginning again and I'm sure that 99.5% of reefers won't be doing that or if your tank totally crashes and you parameters are way off you can kill everything then.