So, as you can see, poor Peaches tail is starting to shred:
Did I catch fin rot here? And if so, is it early enough salt baths should help him? He's got one plastic plant in his tank, but it doesn't seem to be rough, and he swims around and through it all the time with no problem, so I doubt he ripped it...
The one thing that will completely set it in reverse is a warm tank with clean water. For now you should be able to slow it by a fraction by cleaning the bowl every two days and salting the water, but that's only a temporary solution.
Basically the two factors working against you are
-Better conditions for bacterial
-Easier for open skin to become infected
-Stresses the fish
-Weakens the immune system, making the betta vulnerable to multiple diseases
Low Temperatures - You have probably heard in high school how heat willl speed up chemical reactions. 'Protein synthesis' (aka when tissue cells make new tissue cells) is a chemical reaction, therefore warmth allows the cells to multiply faster (within reason... don't boil him!)
- Antibodies, skin, blood, scales, lymph and all other sorts of good stuff are made from proteins, therefore what you want is for your betta to make proteins faster.
-At optimal temperatures, your betta is more likely to fight the bacteria faster than it can multiply.
-When your water is cooler than optimal, your betta will fight the bacteria slower and heal slower.
Speaking of protein, high-protein foods like frozen (not freeze-dried) bloodworms and tubifex worms (I trust Hikari) will help him beef up again after the infection has been stopped.