Lift those pots , do they feel has heavy as the others? They look like they need a big drink. Give them a big drink and let them dry out and then another big drink.
CM is great , 55 days and shes done, excellent yields of some frosty really skanky buds. About an 8 for potency . There is some pheno selection involved but in a pack you will find the CRITICAL MASS pheno. Also grows great outside but may run into mold if humidty runs high.
Your PH is way to high for hydro , thats where your problems are coming from. |Drop your PH to 5.5 - 5.9 and you should be fine. What kind of hydro setup you running? Is it DWC or drip system?
You can use aluminum sulfate or just sulphur . Mix it in your soil like you would lime. But ya make sure you wanna lower your PH of the soil, the MG potting soil is usually acidic.
Do what youy wanna do , they both will work just HPS promotes better flower (bud) growth and since yours are in bud stage then you might as well put them under the hps but same schedule 18/6.
keep doin what you do, 10 hrs light is fine , did it for 4 yrs with an ak47 plant that i had . 10/14 right from the beginning and never had anything want to revegg.
Nice looking setup Flo , how do you manage to change out your nute solutions once system is up and running? Just looks a little tricky to empty and fill up the coolers once the setup is up and running. I have had great reults with DWC , just hated the workload with multiple buckets.
Venting into attic will cause major mold problems in your attic. Hot air meets cold air in attic = damp molded mess. And yes you can use metal halide from start to finish. In my experiences MH produces more resin.
They are preflowers, he did not have to force sexing , they showed in veg. Good stuff . 1 and 3 do not seem to show anything yet so keep close eye on, 2 and 4 are males. Males show first and they will not shed pollen in veg. Nice coloring on the stems you got there.
Peace