Oh okay, I'm sorry I miss-understood your question... I will answer better this time and hope I can answer your questions... First awesome you have a lux meter, I can't afford one, so the app does help...Okay I will try to explain very best I can...I will kinda answer the 2nd part first, Yes I want to keep my inter-nodes as close as possible(with-in reason) I don't keep my light too close, it's not that close..Last Saturday, the light was still positioned 22in over tops..Today, I moved light up 3 ratchet clicks for my light.. I didn't check the height, but will be feeding them in a few mins, so I will update how far above the light is now... Okay on to other part of your question about how do I know when, Like I mentioned in a previous post to ya I really pay close attention to my plants and watch the inter-nodes very carefully, when I see the next inter-nodes , I can judge approx how far away it is from the prior and if distance is getting shorter then I know it's time to raise, but when I raise I only go up very small amounts, I look at it this way, if you raise your light 2-3inches that is min amount of inter-node space you'll have between that set... These I been also purposely wanting to keep the size I want them to be, I was told one of mine can get very huge.. so I wanted to make sure I am in control and stay on top of that...Just keep in your mind how much distance you want between the inter-nodes, you have the lux meter so get as close to sweet spot as possible, then see what the plant is telly you... If the distance at any point goes over 2.5" you know your light needs drop down, but also do that slowly as to not drop to far & stunt...once your in sweet spot , you really just need hold it there, controlled light lifts, but not often and only 1.5" and see how your liking that space, if it's fine take measurement, so you know your sweet spot...so on next grow besides app you can remember look up heights that worked well and should have pretty controlled spacing throughout your grow if you follow closely like I do. I hope this helps ya some???
.. These 4 plants really over-taken my tent rather quickly and still getting bigger for about 7-10 days more, hopefully in next few days the rapid growth will slow down a bit... Because the C.C really starting show flowers now, I decided to switch all the plants over to transition to try and keep them at similar harvest times...the other 3 would another week or more if I had let them, but we not want un-even plants, if them 3 continue then the C.C won't receive the light it should, not all areas are gonna get hit by light, the light's footprint just isn't as big as my plants footprint.
