Sick Betta

My room mates betta has been drifting to it's side for over a week, it's fins seem to "rotting" and it's skin was purple but is now blotchy with white and grey. It's fins seem eaten away. It is obviously in pain, but is a trooper and I sincerely hope there is something that can be done. It is in a tank with 4 neons 5 danues(? name?) an upside down cat fish and brown fish that has a mouth underneath and eats algea and sticks to the side of the tank. The neons, danues and catfish are new, the betta was getting ill before the others were introduced. All the other fish are well. There were 3 other betta type fish that my room mate bought together, they all died and were found covered in clear slime. Please help as my roomy is really attached to his fish and the betta is a trooper and deserves the best.

Thank you so much

sounds like fin rot.

go to google and type in fin rot and you will get so much advise. my fish lives through it, but the other fish could caught it too so i would isolate the sick fish. this is usually caused by poor water conditions and high ammonia levels. i would do at least a 25% water change everyday till the fish is better. depending on how sick the fish is, it may be able to come through this. For me, fin rot has been the easiest thing to cure.

good luck!
(im sure other people will give you advice tomorrow)

goodnight.

what size tank is this? how offen do you clean it? did you put 3 bettas together?

I would also say fin rot but am more concerned about why youve added more fish when you knew that you had an ill fish in the tank.

3 bettas in a same tank!!!!!!!!!!!!my god and pls pls don't use 100% water change daily bcoz the fish can stress as bcoz of that.and it is "danio" rather than "danues". and u need air pump and some biological filtration.

accually changing betta water 100% daily is a good thing for a small tank or even 100% everyother day but it all depends on the size of the tank.... and male bettas if put together will KILL eachother if put together unless they are to sick or weak to fight

ive been around betta and have been breeding them for about 4 years now and theres lots of good websites on them about basic info on there care because they are the #1 fish!

so where u rank discus,angels,black ghost knife ,flowre horn,arowana,oscars????