[AlecFish]

Hey everyone,
I've had this tank setup for a while now and added 9 more neon rainbows to my tank, 3 to begin with. I did a 2-hour drip acclimation and did everything I should have done to get these fish in my tank. I got them Wednesday and the day after I see a spot. I confirmed it was ich and started to do the heat only treatment for ich. I gradually raised the temp to 84F. Knowing heat speeds up the life cycle of ich I was hoping we would be good by next weekend. But no, today after getting back from work I see tattered fins and the beginning portion of their tail be the only thing remaining. Tested it today looks perfect besides the high pH
Parameters-
pH- 8
Ammo- 0
Nitrite-0
Nitrate- very minimal

The store I got them from keeps their pH at 7 so that could have caused the problem in the first place. I will never buy any fish in my life unless I quarantine them for a week. Lesson Learned...

So, whats up with these fish?!?!?!
Bacterial or Fungal?
What should I treat with?
Very bad pic, I know, But should be enough.