[Romad]

My head is spinning with all that you posted. Without knowing the levels of ammonia, nitrite, nitrate, ph etc... in all of your different types of water, you have no way of knowing what's currently toxic for your fish or what he's been exposed to. Do you have any way to test your water levels?

Can you just fill your tank with tap water that's been pre-treated with water conditioner? Preferably Prime?
Are you using all those different water sources because your tap water has high levels of something harmful?

Get him into some safe, conditioned water first and go from there.

 

[Romad]

Can you get your hands on the API Freshwater Master test kit?

In the meantime, bring a sample of your water to your fish store to have them test it. And K Stiles has it right that you need to get some relief for your fish right away. Get some water from your pet store and see if they have Jungle Fungus Clear or Jungle Fungus Eliminator or Melafix. If it is fin rot, those meds should help but I wouldn't start meds until you get him into some good water.

Neenjar posted a great link for giving salt baths. Just don't overdo the salt and make sure it's fully dissolved before you put your fish in.

Good luck and keep us posted.