White stripe on betta

[jesso435]

• pH: 8
• Nitrates: 20ppm
• Water Temperature: 78

I didn't include nitrite and ammonia, because they are in flux. Last reading wasn't great - .25ppm ammonia and 1.0 nitrite. I'm trying to cycle this tank, and this betta has been through a lot because I got him from PetSmart and didn't know what I was doing when I got him. 

Anyway, this white bit started out as a little dot and has spread to a stripe in the past few months. It hasn't gotten bigger in the past few weeks, and he doesn't seem bothered by it. It's not fuzzy, but it is a bit raised. 

LFS owner thought it could be a fungus and suggested sulfaplex since it probably wouldn't hurt my BB since I was still trying to establish my cycle. Anyway, been having trouble getting that tank cycled, so she said to hold off on meds until that was established. I've since upgraded him from 5.5 gallon to a 10, which is still yet to cycle. Long story short, he hasn't had meds in a while, and I'm worried it's getting worse. 

Any thoughts much appreciated. 

[Colu]

You can get white patches from ammonia burn they will eventually start to turn black as they heal if it's ammonia as your tank not cycled and you have ammonia and nitirtes I would do small daily water changes of 30% and add seachems prime every 24 hr to detoxify any ammonia or nitrites till your ammonia and nitirte levels are at zero and your seeing low levels of nitrates