Different products have different instructions on them. I have Super Ich Cure, Nox Ich, and Rid Ich. I was using SIC at half strength every other day for 2 rounds and ich was still present. I switched to NI at half strength for 1 round (every day for 3 days) and it was still present. I picked up RI and online instructions and on the bottle were to use it at full strength up to twice daily (on loaches). I tried this and 2 died after 2 treatments, 12 hours apart. I did an immediate 75% water change.
I'm on a well and I have been very careful about water temperature, but I have been very aggressive with water changes- up to 100% several times over the past week and a half of treatment, sometimes scrubbing out the empty quarantine tank (just water and a paper towel) while fish sat in a dish. I wasn't sure which would be harder on the fish at times, the chemicals or the massive water changes but I felt like I had to do something since the meds alone weren't working.
After the 2 loaches died yesterday I am frustrated and feel at a loss for what to do next. I have not missed any treatments. I have followed instructions closely. These loaches came from a new store in our area. They were very small and I had a few waste away and die. They were replaced by the store each time- this is how ich ended up getting introduced to the quarantine tank. They weren't the strongest looking fish in the first place but just before ich took over the 4 of them were starting to look pretty good. I am feeding frozen foods and have the tank at 82F.
Was it wrong to use the Rid Ich (malachite and formalin) at full strength?
Nox Ich (malachite and NaCl) says to use daily for 3 days- is this a mistake?
I wonder if the super ich cure was old and not effective any longer- it was stored for many years.
Was I too aggressive with water changes? Not aggressive enough?
Would you suggest trying to treat this with water changes alone? (2 tanks, moving fish between them daily and scrubbing each out between use?)
The 2 loaches I have left are finally showing fewer cysts. They look like they've been through hell but they did eat some bloodworms today.
If it would be useful to read more details about the past few weeks I'll link another forum where I posted about this (I couldn't remember my username/password here at first). I was tired and feeling a little dramatic when I wrote it- my apologies

http://www.eastcoastaquariumsociety.ca/ ... the-battle
Thanks
Jen