My son's Betta experienced a really bad case of fin rot. The bottom left is one month ago and the top left was a couple days ago. His original tank had a terribl algae outbreak and was only 3 gallons. I upgraded his tank to a ten gallon planted and added some snail friends. He is much happier. I also added pearlweed to the front to create a carpet effect.
https://www.reddit.com/gallery/1diyk0y
Posted by mama-bear-1029