| Hi Renee, so if you have control over temperature do use it to speed up the process. 76 F os plenty for koi. Are you sure you are looking at ich spots?
I also noticed you are using fish aquarium products. Kinda expensive for larger ponds and often weak in dose. I'd check out some of the on-line koi dealers for some pond sized product. I like Eastern nishikigoi inc ( I think they advertise here?). But there are many others.
As far as eating goes, fish with ich that are overwhelming them usually show it in their behavior- breathing, fin movement and twitching and eventually lose of appetite. The spots you see on the tail are not too bad but you have to assume ( if it is ich) that those same number of spots are also on the gill- which is not so good!
The hydrometer is not really to valuable for salt levels for koi treatments as they are relatively low ( compared to say saltwater levels) and read such a low level that it is not easy to be accurate with a hydrometer. It is true that salt and mal green / formalin has been known to be dangerous but that is usually in very warm water. The idea of the salt is to have something to put some stages of the ich parasite in osmotic stress. Again it will not kill all stages but act as a barrier to nomal population growth.
I'd look into getting an inexpensive microscope or have a club member stop over to do a scraping for you. Does your dealer scape his fish? JR |