Welcome to SLA 
A great number of people here are using the nail salon solution for curing their parts (I am one of those). Those bulbs are actually 385nm.
I too use mainly tough resin, and I too use 99% IPA. Leaving your parts in IPA too long (especially 99%) can adversely effect your parts, so make sure you aren’t soaking them much past the 10 min x 2 rule. Also make sure they are thoroughly dry before curing.
I tend to undercure my tough parts. I feel they are stronger and more durable. Take a look at the video by @mkmachining here. Judge for yourself.
- Kevin