I assume the fish are dead by now but the ruby barb in the picture has white spot, not epistylis, which would be treated with salt.
If you get white spot in a tank, do a massive water change (80-90%) and a complete gravel clean before raising the temperature. This reduces the number of parasites in the water and means fewer parasites to infect the fish.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.
You can do a 90% water change and gravel clean every day during treatment if it is a bad case of white spot. Again the big daily water changes help dilute the number of parasites in the water.
--------------
If the white spot is not responding to heat treatment (30C/ 86F) for 2 weeks, then use Malachite Green or Copper to treat it.
Warning: Malachite Green is a carcinogen (causes cancer) and should be handle with care. Try to use a liquid version instead of a powder form because it is safer to handle. Wash hands with warm soapy water after handling Malachite Green or working in an aquarium containing Malachite Green.
Copper is poisonous to invertebrates (shrimp, crabs, crayfish, etc). If you have inverts in the tank, remove them before using copper, and do a few big water changes and gravel cleans before putting them back in the tank.
--------------
In cases that aren't responding to heat and when you can't get chemical treatments, you can move the fish into a clean container of water each day for a week. The parasites drop off the fish and when you move the fish into a clean container with clean water each day, you move them away from the parasites that have fallen off and they become free of white spot after a few days to a week.
The following link has more information on white spot and these methods for treating it. See first post on page 1 and 2.
This is a common question that is often asked, what is ich and how is it recognisable and what causes it? The real term is ICHTHYOPHTHIRIASIS. OR commonly known as white spot. It is an extremely comon parasite that affects aquarium fish. It is highly infectious and potentially lethal and...
www.fishforums.net