I don't currently have a quarantine tank (I had no idea what was involved when I impulsively got a tank over a month ago, but until this outbreak I was enjoying myself immensely).
My husband and I agree that I could upgrade my 15 g tank to the Fluval Bowfront 45 g which is currently on sale at a nearby local fish store. I wasn't going to do that until maybe November, but I am wondering if I should just spend the money now, and get the larger tank which comes with an adjustable fluval heater - so then I could heat up the 15 g to 86 degrees (and just store the larger tank until I'm more organized).
Potentially I guess that gives me two tanks to work with, but only one which is cycled.
Wouldn't the spores be all over all the fish and the substrate by now? So if I transfer fish to a 2nd tank somehow wouldn't I then just be spreading the Ich to both of them?
So confusing. Meds, tanks, heaters, $! Don't know what first step to take.
Salt wouldn't work because you have cories. They whole tank should be treated because ich hangs around in the substrate and even in the water I think. Treatment should continue even if the white spots go away because it takes more to wipe the ich out entirely.
There are three stages of the ich life cycle, but I am not sophisticated enough to name them or where the ich is in that cycle. You could probably do a search in this forum. A lot of people have explained it when helping others with ich.
When you are using meds - make sure to remove the activated carbon from your filter - or the filter bag entirely, but keep the filter going. If you raise the temp (which should be gradual) and don't use salt (even if you did) you need to make sure the fish get enough oxygen which becomes less abundant with increased temperature and meds. If you have an air pump, use it. I recently got one because I was so worried about oxygen that I would sit by the tank for hours to make sure the fish aren't gasping.
If you need to make an emergency QT tank - which you probably won't unless you have to move the shrimp (I don't know about them enough), you can make one out of household stuff in a pinch until you can get a better one. Again, google that and no matter what, if you use a plastic container from home or buy one at rite aid or,wherever you could get one, it cannot have been cleaned with soap. Warm water only. I was lucky enough to have a plastic container that had never been cleaned with soap because it was brand new.
Other than the possible need for a QT for the shrimp, you may be able to get by until you do more research on the best way to have a QT. I think a QT is not supposed to have substrate especially when treating for ich because you don't want the ich to latch onto it. I am not sure if a QT needs to be cycled per se but the water needs to be pretreated with prime, the same temp, and a ph that is not far off from the main tank so as to prevent stress or shock.
Hopefully this will start you in the right direction and additional research will give you more specifics.
Hopefully more sophisticated advice people will also reply to your post. You might consider buying a better heater that is adjustable temperature wise.
A lot of stuff is cheaper if you order off Amazon. A lot of people want to support their local fish stores and patronize them, but if cost is an issue, Amazon is good.
Keep us posted and I hope this helps you a little bit - just know I am an not an expert by any means.