I have a question please, I have RQS Northern Ligh...

depends on the current pot size. when the canopy is as wide as a starter pot, it's usualyl okay. if you can see more than a rare root at bottom, that's also a good sign. if the substrate is recently irrigated, it'll hold together well with a root system. that's what you are waiting for... so that when you handle the transplant it doesn't fall apart in your hand. pot impacts size of plant if the roots get cramped, so don't wait too long or it may take a second to resume vertical growth. had some plant sin solo cups for 6 months before. they were rootbound and still took off quickly after transplant, but their size was limited for months. staying too long at any pot size only slows you down -- which is somtimes a useful tool. I don't like autos but have grown somewhere between 10-15 of them and they really don't have to be treated differently whether it's fertilization or tranplanting in my opininion. Those that htink they need less just feed too much to start and the context of it going into flower phase makes it pickier about nutes sooner. I never saw transplant shock from doing my normal process of up-potting when i've grown the handful i've planted. MAybe people are really rough with their transplants? i don't know why this is a thing. I never see transplant shock with my photoperiods (300-400 transplants? i do 2 transplants per plant, i could count this up as i have records, but the guesstimate is close enouugh to drive the point home), either. Seems like a less than 1% type risk and the benefits of not having a tiny plant in a huge pot are more heavily weighted in my perception of things. Makes watering difficult, raises risk of pathogens and pests with stagnant, wet substrate for longer periodds of time than necessary. This is one of those things like, "flushing at end of harvest to reduce minerals in a plant," people repeat it but i don't think it's substantiated by anything other than avoiding responsibiity for a self-inflicted mistake of aggressively handling a transplant. fwiw, you cannot reduce minerals i a plant by flooding its roots. the plant has no excretion system for such things. physically impossible and a poorly formed hypothesis to start.

It's really best to get autos in their final pot ASAP as to not disturb the root system too much. I start seeds in starter pucks(Rapid Rooters) and plant the puck about a week after sprouting typically. At week 3 you're about to start preflowering if you haven't already, you don't really want to transplant during flower so you need to hurry.