Looking good! I'd like to get T5's for vegging too, but right now I'm doing a SIHLA grow (stuff I have laying around).

I'm using the ProMix high porosity, watering with filtered tap water, and I haven't had any ph issues. Water is around 7, and runoff is around 6/6.5 or so. Plants seem happy. They didn't need nutes for the first 5 or 6 weeks.

As for lst, I'd say it depends on your plans for them. Potential mothers, bud quickly, veg for a while then bud...

What kind of bud lights you got?