Beta, turned white over 95%,listless

Question
New fish owner. Just noticed formerly red Beta fish is now 95% covered in white slightly fuzzy appearing substance and is listless.  Seemed okay a day ago (certainly nothing close to current condition).  Barely breathing, one fin not working, goes from being vertical to head down.  How do I save him?  We did a 90% water change, temperature is approx 78, water is conditioned, has an air pump.  LFS staff is not very helpful in general (have not asked about this issue).  Can go today and get suggested Rx, etc.  THANKS. - will

Answer
Hi Will,
Sorry to hear about that.

Sounds like your betta definitely has fungus such as a Columnaris infection which is really a bacteria yet appears as a white haze or slightly fuzzy patch on the fish. Sometimes it can also be stringy.

It can be caused by dirty water conditions, temperature too low, stress, injuries or compromised immune system

Your betta has a pretty severe case of it and I'm not sure how high his rate is of recovery. In my experience of fungus medication has been that "JUNGLE BRAND" Fungus clear is very effective for clearing out infections such as these. Likely your betta is in a small setup so dosages for 1 gallon is-

1 Gallon Dosage:
Dissolve 1 tablet in 10 tablespoons of water. Add 1 tablespoon of concentrate mixture to 1 gallon.

I have a different method for treatment regimen than what the directions say but this has worked out better for me with my stubborn fungus cases multiple times-

*Change 50-75% of tank water everyday (to remove pollutants, old medication, and bad bacteria)

*Redose with new medication after daily water change.

*A little aquarium salt added also is good to help deter the fungus though it's not completely necessary.

~Treat for as long as fish shows symptoms and perhaps one day after the fishes skin is completely clear. Then continue doing daily water changes but with medication and salt.

*~*Beware the petstore advice. They often are misinformed themselves and don't really know the details and correct, proper methods of treating sick fish~*~

I hope your little betta hasn't gone too far and best of luck!

Karen~