Hey LostInTheWoods,
mr.bond here. so looking over your posts... in the pics on this thread, the new growth is a bit yellowed and has very small leaves, with some slight signs of curling. first, i'd rule out a couple of things.
boron deficiency - i'd peg this as highly unlikely considering you are growing in promix, which comes treated with micro nutrients.
excessive light - nope. in fact i usually keep my light even closer. even according to CaliGrower's chart, at 75% ballast output on a used 1000w, your plants in veg are only getting about 50% of the sun's PAR at the moment. heck even at 100% ballast output @ 26" youre still well below the sun's PAR (>75%)
pH issues - hmmm... im doubtful but its worth researching. when microbes eat organics the pH will rise a bit. since you havent been giving it full strength nutes, there might not be much of a pH rise, and the dolomite lime you have in there might be keeping the pH quite a bit low. when your soil dries up a bit, water until it starts to drain from the bottom. take a sample of that run-off and pH it, see where you are at. if it is a pH issue, it happened recently. the rest of your foilage looks quite green.
Nutrient issues - well you know im a fan of the GO line so i dont think this is it. although i would say its time to ramp up your nutrient schedule. use the GO Box feeding chart, and give it the works -- BioThrive Grow, BioWeed, BioRoot, Diamond Black, BioMarine, Ca/Mg. For now the feeding chart on the box should be fine, it is enough to cover all the bases without getting excessive.
Beneficials - if you want explosive root growth, and those organic compounds to be broken down, get moving on adding some beneficial bacteria/fungi to your soil mix. cheapest/quickest/most effective way to do it is to use that tea formula I linked you from Heisenberg. you can foilar spray a bit and also add some as a soil drench. this will jump start the roots if they are struggling. and also aid tremendously in water uptake, nutrient uptake, and disease resistance.
so yeah, your light is not too close. but light and heat are two different things. i think radiant heat exposure might be what is stunting your new growth. i didnt see anything about your veg light being cooled or having a hood, maybe it is but i didnt see it. 1000w lamps can put out quite a bit of radiant heat. for me it isnt much of an issue because my 1000w runs in an 8" vented hood with about 400cfm fan attached in a closed-loop config, however, without active cooling, the 1000w can easily hit 160F within 1 minute.
now im not saying that the heat issue is the definitive reason for your stunted growth, but it seems like that may be it. i have experienced similar stunting with new clones and high temps, and for me it was about a 7-10 day turnaround on recovery when put into a proper environment. some clones didnt recover, but you have a bit of a root base already so you should be ok. plus in the 2nd pic on this post, you see that one leaf thats curled over quite a bit, behind the new growth. that isnt typical for healthy growth. in my experience curling is usually due to temperature issues.
well thats all for now. ill wait to hear what your cooling situation is like for your veg lighting. even though you have reasonable ambient temps, those can raise drastically due to radiant heat exposure. let me know if you have any questions!
cheers
mr.bond