White Widow ( First Grow )

Decided to pull the trigger on another light ( mars TSL-2000 ) and installed the scrog net. One plant is growing noticeably slower than the others but isn't showing any signs of deficiency and i know it wasn't over/under watered. Oh well, so to compensate i moved the larger ones a bit closer to it before installing the net as i suspect this will help fill it more evenly with the more rapid growing plants. After adding the new light i'm running into temp issues even with the drivers mounted outside the tent, but i know that most of the heat is coming off the cheap COBs from amazon. Things were getting up to 28 Celsius unless i have the 190 CFM fan cranked to max settings which would cool things down to 25/26 during the day. But this is causing lots of neg tent pressure and i'm having to refill the humidifier twice a day which is very inconvenient. When i flip them to flower in the next week or so i will have the lights running at night to try to keep temps down and not have to tend to the humidifier as much. The largest plant is confusing me a bit as its leaves are lighter green indicating low N but its tips are still clawing a bit like its getting too much N? So when i've been feeding the larger 2 i alternated the strength of nutes from 1/2 to 1/4 back to 1/2 ( still 1/4 strength for the smaller 2 ) and Recharge compost tea once a week. The larger plants take 3.5 litres of water about every 3 days and the smaller ones i've been only giving about 2.75 litres. I might upgrade the extractor fan if i cant keep temps down during the first week of flower, i'd like to buy the AC cloudline T6 as it auto manages temps for you but alas amazon.ca is out of stock. I will be checking every other day to see if that changes and order it once it becomes available. I also noticed after tucking leaves today that 2 plants had developed pistols. See you next week.