Retarded plants update - Yellow leaf problems - Help me save this 5 footer!

So a bit of an update: Everything seemed to be going well, I had to murder the little fella as he turned out to be male, the other 2 have been coming on leaps and bounds until noticed that the smaller of the 2 had a huge infestation, in the end I had to dose both of them with insecticide a few days ago (not the first time) the smaller one (which had the infestation of spider mites i think) is fine but the bigger one (about 5 feet tall) is unnervingly turning yellow at a fast pace, I had noticed this before I dosed them, I have been watering her a lot more than the smaller one as and when she needed it including during the day (very hot sun here in Spain the last few weeks) they have both been fed 3-4 times in their lives with VERSOL 20% solution N-P-K -8-4-10 (i hope that means more to you ) some pics

its probobly root bound

Hmmm not sure about this as i recently replanted it to a bigger pot (max 1 month ago) I might have packed the soil a little tight could that have affected it?

Yes. Pot likes nice airy soil. It also helps it dry out more by the time you water next.

Hmm, I dont quite understand what do you mean by "helps it dry out more by the time you water next" the big one gets watered daily and if a day is missed it is usually very dry and thirsty. I have started them on Bio plant food, daily. Should I start them on a 12/12 hour light cycle or just leave them outside and let nature take its course?

Cheers

The insecticide will not fix the spidermite issue. You have to use mitacide in and surrounding the grow area, as for the affected plant, get it away from the others and tend to the good ones first and the mite one last, then wash your hands.