How do you prevent fin and tail rot?

Well, 1 easiest way is to change the water everyday and put alot of medicion in. If your betta has a light fin rot, you could put in about 10 or 20 drop, if your betta is in a advance fin rot, make sure you put a lot of medicion in! One other way from making a whole tank fill with deceses is to remove all the fish out of the tank, change the water, and put back the fish thatis health and keep the sick one out in another bowl. If you saw the fin rot but it is already in advance, there is not much of a chance that it will be alive. Sorry!