Orange Sherbet & Purple Lemonade Auto

you will have a small stretch but rule of thumb, when plants flower they double in size. 3-5 weeks are the vegative stage 4-6 weeks is the stretch phase 6-10 weeks is typically the flower stage this chart will help more so you can understand what is happing, you should be ok, happy growing

Ah, the Mars Hydro lights, I currently run 2x Mars Hydro 150w TS1000s, so pretty close to what you are doing. I keep em high and let the plants grow up into them. Seedling/Sapling 100% power - 60 inches, this'll put you around 9000lux, 70umol. Veg 100% power - 36 inches - gives you 20-50k lux and 150ish-400ish umol Flower 100% power- 18-24 inches give you 50k-70k and 400-700ish umol. Hope this helps.

I think you have toxicity. Check the EC of runoff. I'm also not intimately familiar with your nutrients but make sure you're going low on the N. Otherwise check the pH of feed and runoff, if you're overfeeding, your runoff will probably be super acidic, causing uptake issues.