I have a sick fish with green spots on it, and I bought the appropriate chemical, but after 5 doses the fish still isn't cured. I even wait between doses. Any suggestions? Thanks

Sometimes it can take a lot of effort to cure a sick fishie! I've had it take up to a dozen doses to cure a disease. When that happens, it can help to "aim" the dose just above the sick fishie, making sure that there are no other fish or objects in front of it when you administer the medicine. It's a bit tricky to do that, though, because the fishies won't hold still.

I would have to think twice about how much the fish costs and/or how hard to replace by re-breeding before I would spend that much on medicine. It takes a little longer but the customers will eventually buy even a sick fish and there's always the trusty old trashcan.

That's exactly what I do when I'm actually playing Fish Tycoon instead of testing it. The scenario I described occurred during testing.