we have 2 bettas in separate tanks.
we woke up this morning to find that my husband's blue crowntail betta has what could be ich. I'm attaching a photo. His fish is 100% blue, so any white that shows up on his body is what appeared this morning.
He has a big white blotch on his face, and his top fin has turned almost completely white. This happened overnight, he didn't look like this AT ALL last night when we went to bed.
He is in a 5 gallon tank with a filter and air stone. 2 silk plants 2 small plastic plants, silk leaf hammock, heater, boat decoration, and gravel substrate.
My betta is fine, it's just my husband's betta.
I know I need to quarantine him in a small bowl and treat him with medicine... but can I have more specific advice? What would be the best medicine? Is this ich for sure (i've never had a fish get sick before), do I need to clean 100% of his tank before I put him back in, or 90%, 50% or what? when I quarantine him how much water should I put him in... and should it be tank water or fresh new water?
Please help :(