burn mark betta or?

[liberator123]

ive always had a bad feeling for adding a heater to my tank, but since i was advised to make the temp around 78, i added a heater in. my betta now has a wierd brown spot on the back (see picture). i am wondering what it is. was it caused by burn from my new heater? is my betta sick?

 

[AngelFishGirl]

Could be the heater. But I am wondering if you test your water. Could it be ammonia burn?

 

[Mebbid]

I seriously doubt that it's an issue caused by the heater. Do you have any older pics of the betta?

Its entirely likely that it's just a color change or stress coloration on the betta.

 

[liberator123]

He died just recently... the redstuff spread all over his body. I tried to help him by quarantine and salt bath. Ive been researching what it could be, and I THINK it might be velvet OR a bacterial infection. And from my research, these are highly spreadable, and my other fish started having different colors appear (gold patches on my cory julii, and my platy starting to turn reddish), so Ive decided to do a 100% water change and started coppersafe treatment (im going to also get antibiotics today and add that). I also removed all the plants and gravel (to get rid of possible spores and parasites). So far, the colors of the cories are returning, and my panda platy is less red.
Im probably going to do a 25% water change everyday for a week