I have two betta fish males. One in my room, the other in my office room. I've had the one in the office room for about 6 months. He came in from a family that wasnt able to care for him anymore. His water was pretty dirty and looked poorly taken care of so I bought him to give him a better life. He came in a 5 gallon Fluval Chi tank and I cleaned his water, gave him plants, and everything a Betts fish needs. Everything in his tank is fine, I've had many Betts before so I'm sort of an expert, but none of them have gotten sick before. A week ago I started noticing that the tip of bis bottom fins are turning white. Not translucent or spotted, they just look like the got dipped in white paint. He's still his usual self but with white on the tips of his bottom fins. Whats wrong??