[wannabefishguru]

you could try this, i know it says for ich but the salt treatment can realy help, especially with cory cats, because they are scaless

#1. Salt added to the water. Salt will kill ich. Just as meds will. The dosage needed for this is 1-3 teaspoons per actual gallon of water. One strain of Ich has been reported to withstand as much as 5 parts per thousand of salt* so do not rely on light salt dosage to be 100% effective. Most strains will succumb to low levels of salt though
My personal recommendation is 2 tsp. per gallon as a target. This gives me a good solid level with a 1 tsp. per gallon buffer zone in both directions. In other words I can be 1 tsp. per gallon higher than I think I am and my fish should be OK, or I can be 1 tsp. per gallon lower than I think I am and my ich will still die. Many people do quite well with 1 teaspoon per gallon but I don’t like variables so I go higher. This buffer zone is more necessary with hobbyists who don’t know the actual (vs. estimated) water volume of their tank.
To add salt, mix it in small volumes and add to your tank. It is not recommended to dump salt in directly as a solid. My method is to mix it with a bucket of tank water and siphon it into my filter with a ¼ airline. This ensures it is mixed, and adds it slowly to a high flow area to be further mixed as it enters the tank. I add ¼ tsp. per gallon once an hour for four hours. This brings me to a level of 1 tsp. per gallon in four hours. At this level, I am far more relaxed and will generally increase it to 2 tsp. per gallon in ¼ teaspoon increments every 3-4 hours. I always watch my fish closely for reaction. Once I am above 1 tsp. per gallon, if I see signs of increased stress I will slow things down and allow my fish more time to adjust.
Whatever method you use to add salt is fine, but raise the level slowly and mix it well. It will be easier on your fish to do so. At the end of the planned treatment period, I do not worry about quickly removing the salt, I simply go about my normal weekly maintenance without adding any more salt, and eventually it will all be gone from the tank.
Salt is by far my preferred method of treatment, it is less expensive, far less stressful and every bit as effective as ICH meds. Furthermore it is not affected by organic carbon levels which to me makes it more reliable. Filter carbon will not remove salt from the water so if you are using it you do not need to remove it as you do with meds.
As far as what type of salt, you need NaCl. I use table salt, many folks use pickling or canning salt. Iodized salt has never been harmful to my fish, The levels of iodide and other agents are too minute to be a factor. Freshwater aquarium salt is also NaCl as a rule, but is usually more expensive. The only thing I would caution against would be Marine salt mixes for saltwater tanks as they contain many things unnecessary for the treatment of ich, and stand a good chance of changing water chemistry.