A retired research scientist is where I got my information from. If the gills are damaged enough, they won't be able to process the oxygen even with the extra aeration.
The higher temperatures have been known to kill fish, and what is your backing to say 84 is a waste of energy?
I know this is a planted tank, so salt is not an option. This is the procedure I'm referring to, and why I think it's important to not raise the temps too high. I'm just saying, if it's not a necessary in the cure, why take a risk if it can be fatal to the fish along with the ich?
Salt and heat for FW Ich:
1. Increase temperature to 80F -84F. Ich is principally a temperate zone gill parasite and fish may have issues getting enough O2 in warmer water. Start at 80F and if there are no signs of respiratory distress (labored breathing and/or hanging at the surface), increase to 84F.
2. Add 1 level measuring teaspoon per US gallon of salt (ordinary table salt) to some removed tank water, mix well to dissolve and add it back to the tank in the path o the filter outflow or other current. This can be done while the tank is warming up. If there are no signs of distress (as in #1 above), after 12-24 hours add another 1/2 teaspoon per gallon in the same way. Do not use "aquarium salt" as that has no legal definition.
3. Both salt and heat interfere with the division/reproduction of the parasite (the stage after the parasite falls off the fish and rests on the substrate or decor. It is effectively invisible at this stage). At and above 80F, the life cycle is ~3 days total. Therefore you need to hold at the elevated temp approximately 10 days (or at least 3 life cycles).
4. Some to many folks like to vacuum and partial daily during the elevated temperature period. If you do this, the make-up water must have the 1.5 teaspoons per gallon of salt pre-dissolved in it, and it must be at the same temp as the tank before it is added to the tank.
5. At the end of the 10 days, reduce the temperature to your normal operating level.
6. The salt is diluted out by water partials after the ten days are over. Routine 50% partials will effectively remove it after 4 partials. These may be done daily if it is desired to get back to normal operational levels more quickly (I do). At least the first 50% partial should be done immediately after the end of the treatment. After one 50 partial, the salt is down to 3/4 tsp/gal. After two 50% partials it is down to 3/8 tsp /ga. After three partials it is down to 3/16 tsp/gal and after 4 partial is down tp 3/32 tsp/gal or effectively undetectable.
Nota Bene: The disappearance of parasite lesions from the visible surface of the fish does not mean the parasite is gone. It is a gill parasitre, and if not cleared by the full 10-day treatment it may persist chronically in the gills.
As with other medication therapies, just about everything about the above process is critical, particularly:
-heater malfunction or adding cooler water can delay the cure, further stressing the fish.
- sloppy measures can adversely affect the fish.
-failure to pre-dissolve the salt can adversely affect the process.
-some folks have reported strains of Ich which required higher salt concentrations than what I use. I personally have never run into one of these strains. If there are such, then higher doses are in order, and could be increased at one-half to one level teaspoon of pre-dissolved salt per 12 hours. The timeclock would for ten days would start when the salt content is where you want it to rum. Maintaining stable temperatures is quite important during the process - temperature fluctuations themselves can mimic the reported effects of so-called difficult strains.
-high heat with gill infections of any sort can be highly stressful if the O2 levels will not support the fish easily. W atch the respiration rate carefully throughout the process.
