Ich; White Spot
Ichthyophthirius multifiliis
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Description:
Ich is a parasite that burrows underneath a fish's skin. They cause the fish to be dusted in white specks, sometimes compared in appearance to salt or sand grains. The fish may dart around and try to rub against objects in its tank. This disease can actually be quite lethal, but fortunately is very easy to diagnose and treat. The parasites will multiply in greater and greater numbers so it is important to start treating right away when detected. It is very important to note that just because the fish no longer have white spots that you may assume they are all dead. They will continue to live and reproduce in the water and surrounding tank after they have fallen off the fish. This is why the appropriate amount of heat is important. It would take weeks for the life cycle to complete at low temperatures! You must continue treating the tank for at least one full week in order to kill ALL the parasites (if tank kept warm; longer if not; see treatment below). The parasites on the fish cannot be treated; they are only susceptible to medication in a pre-adult phase of their life cycle, right before they become adults and attach to the fish.
Treatment:
Raising the water temperature will help to speed up the life cycle of the parasites (upper 70's to 80 if your fish can handle this; temp of 90 can sterilize some fish. Try for 84, while gradually reducing temp as problem is cured). Salt baths are effective in getting the parasites off the fish. Salt baths are also beneficial in that you cause the parasites to fall off while the fish is in its bath water, then you return the fish to the tank without the parasites, so they won't be present to reproduce in the tank! Products containing copper salt are very effective (note that this will kill snails) such as Coppersafe or Aquarisol. A number of other products can be found in stores specifically designed for Ich, but remember that the harsher the chemical is, the more stress it will cause to the fish too, not just the parasite. Malachite green is not suggested for scaleless fish like catfish or loaches, or some other fish such as tetras. Treat once every 3-4 days for 4 treatments, changing 50% of the water before every treatment. Continue this treatment for about 2 weeks to ensure death of all the parasites. Remember, they're only susceptible to the medication during one phase of their life cycle which is a 3-day period.
Prevention:
A stressed and weakened fish for whatever reason will allow a dormant parasite to invade the fish and start multiplying. Eliminate stress due to poor water conditions, changes in temperature, bullying fish, etc. Quarantine new fish and plants to ensure you don't bring parasites in from outside sources. Do not cause any drastic changes in temperature in your tank. Always float new fish in their new tank for at least 15 minutes to allow the temperature to stabilize and match before releasing them in a new tank (remember if you float in a bag to open it, as the fish need air to breathe). This is a very common problem in new tanks that causes new fish to contract the parasites, alongside poor water conditions in established or establishing tanks.
but now he has major stress lines and is very twitchy. by twitchy i mean that he'll dart as fast as he can across the tank, then stop suddenly as if someone has pulled his brakes. then he'll do the same thing in the other direction. it's almost as if he's flicking himself but there isn't a lot to flick on because he only has one plastic cave on bottom & a silk plant on bottom. 
