Three INCHES. This is not necessary unless the undergrowth is very dense or your humidity is high enough to cause mold worries.
You can start with MH to reduce stretch then switch to HPS after 2 weeks, but if all you have is HPS, and you have appropriate watts for your space, stretch is going to be mostly determined by genetics, although controlling night temps so the day/night difference is 10'F or less will help too.
stinkyattic Reviewed by stinkyattic on . Neon green with Rust spots Pls help I think that I have a phosphate df, I got the rooted clones on 10-27 they were in rockwool, cut out and transplanted into square ½ gallon pots, I didn�??t feed enough I gave 1 ml of bio grow per gallon with 1 ml superthrive per gallon. Watered till I saw run off, also mixed neem oil with half strength dutchmasters pen, and Dutchmaster Grow and lightly sprayed before I took them in the garden. I then waited until 10-30 and watered until I saw run off with only ½ strength superthrive per Rating: 5