Just wanted to provide an update to help anyone dealing ich who may read this post. It took me a few days to get the treatment started - big mistake. About half of my fish died in those few days.
Another no no, I fed them during the treatment and there were a few small scraps of food on the bottom of the quarantine/treatment tank. They ate the those scraps and the rest of my fish died. Just devastating since my baby albino bristlenose pleco died too.
Originally I thought it was my pleco that had the ich, but now after researching their life cycle it's obvious it was the chilis.
I waited 3 months and did a hard reset in my tank before adding any new fish. Then I tried again with another 6 chili rasboras. I saw a couple spots on some of the new fish, but they told me they had already quarantined and treated for ich so I added them to my tank.
Third no no. Now only a few days later they're covered in spots literally overnight. I should have just treated them and trusted my gut.
Now I'm treating them in a quarantine tank at half dose, waiting 3 days then doing a total water change, feeding them, and treating again. Allegedly the ich should be dead in my tank without fish in about 7 days, but I have also read it could take a month to go through their full life cycle. I read somewhere it could take up to 10 weeks or even 6 months, but I think 30 days is a safe bet. Worst case I'll have to retreat if it's still an issue after quarantining for 30 days. After the 6 days of treatment I'll change the water again and leave them in quarantine until the 30 day mark.
Moral of the story is always quarantine even if people say they already did.