I would have to say if you have not giving them any nutes then the soil was abit hot, can you take a photo of the soil bag? Or where did the older soil come from? Try and get some nice Organic soil with low ferts, make sure there is no time release stuff in there otherwise that soil will stay hot for up to 3 months.. But all that aside the new growth looks very nice, have you dropped the light today?
I have given them 0 nutes as of now. I dont have the bag but you can find it on google easily, the soil i used was Bio-bizz Allmix. Somewhat a 50/50 of reused and new soil. as they direct on their homepage hehe.. but some of the old soil is from other plants that have been fertilised of course, so possibly some leftover liquids in the soil from that, even though i flushed it pretty good (i thought).. Well the only one still seeming to struggle is the black russian, the others looks like they're moving on a little bit now.
Also check your tap water report for your local area online, I use tap water and I bet you do to, An organic soil should maintain a good p.h regardless but old soil and hot soil may be throwing your p.h off, then you could have a nutrient def.. Maby nute lock out... Im on a tight as hell budget so I gotta do as much reserch as possible so nothing goes wrong, this info is just what I have read from some respected growers, Have you got a thermostat with high and low?
I Ph my water before giving it to the girls, trying to hit around 6.5 or so. For that i use lemon drops (SmokerJoe's advice) it works great.
If i dont do it i'll have water of around ph 8 which is bad
My thermostat is dead lol, it died in the beginning, and yes i know.. bad, bad me for not buying a new one yet.. but i'll get one soon i promise! I just havent had any problems really, so i havent taken that so heavily, even though i know it's a MUST!
When your plants are 4"-5" tall and have 5 nodes of growth I recommend you begin feeding 1/4 strength nutrients and gradually over several watering work up to full strength nutrients. Your larger plants appear ready to receive 1/4 strength nutrients. I use General Hydroponics Flora series 3 part nutrients that can be mixed for all stages of vegetative growth and flowering. General Hydroponics Flora series can be used with hydroponic, soil and soiless mediums. I use General Hydroponics Flora series nutrients and use nutrients every time I water unless I am flushing.
https://generalhydroponics.com nutrients flora series
https://www.growitbest.com general hydroponics Flora series performance pack
Hey KingJohn, thanks for the input, me and Kjell are talking about starting to use generalhydroponic's for our soil grows, as he has been experimenting with it on his outdoor girl hehe.. So funny you should mention it
As of now i use Bio-bizz for my girls, which has been just great as well, besides from me misunderstand directions hehe..
Tonight i will start 1/4 strength nutes if not a little lighter on the two biggest ladies, and give the rest of the girls plain water. They've been drying out nicely and the soils almost crumbly on some of them, so i think it's time ^^