I know that using medication to treat this parasite is the #1 recommendation but unfortunately the only medicine for it at my LPS is insanely expensive and sadly I just don't have the money. I'm very slowly upping the temperature of the tank. The last water change I did was a 10% the day before yesterday. The parameters as of today are: pH 7.2, high pH 7.4, ammonia 0, nitrite 0, nitrate 20, and it's a 10 gallon tank, if that helps.
Only one fish is showing symptoms. I haven't seen any white spots yet but she's been rubbing her gills on the side of the filter, the decorative rock and just about every other hard surface in the tank, and they look very irritated; they're a dark pinkish color and inflamed. She'll go from swimming around like crazy to being really lethargic in a matter of seconds, and her appetite has dropped. She's still eating some but she's losing weight and probably not so much from the not eating but also from all of the stress.
Yesterday I added 2 tablespoons of salt to the tank, about a teaspoon at a time every fifteen minutes or so, so the salt wouldn't hurt the fish. They seem to be doing fine this morning. Daphne isn't rubbing against things as much and the others are swimming around pestering each other like they normally do.
So my question is how often do I add salt to the water, and how often do I siphon out the bottom of the tank while treating the tank over the next 2 weeks? I asked the guy at the pet store but he didn't really seem to know what he was talking about (first he tried to push the medication on me like a crack dealer desperate to make a sale, then he said to add the salt every day and didn't even mention that it could hurt the fish) so I thought I'd ask some people who have experience in this area. Thank you so much for your time.