ok so I haven't updated this post in a while seing as my plants were really not picking up at all, with the exception of 1. This was after I nuted them with half strength ionic grow. It was doing really well and got real perky again whilst all the others were still drooping like a mother fucker. The newer leaves on the others however were looking alot more green rather than having the large red stripes through them.
ANYWAY... I let them dry really thoroughly for 4 days until the leaves on the perky one started drooping a lil this morning. I gave them more of the nuted mix, but was really careful to not give them too much! I reckon about 1.5-2L between all of them. Maybe 300-400mill each around midday (5hrs ago) and checked this evening and THEY ARE ALL PICKING UP!! The lower fan leaves on all others are really trying to raise upward and the higher ones, whilst still dropping a lil, have raised ALOT.
I reckon the transplant to the new soil (some super-duper advanced grow shit) fucked em up good n proper (as it burnt tips on several lower leaves) but I fixed this by transplanting back to the old nute-free soil. BUT,.. I reckon I must have seriously overwatered them then. I gave em a good 2L each and I think they just couldn't handle it. The one that picked up well was the one left by the open cupboard door and consequently dries quicker. I also think they had N, P & K deficiencies shown by the red stems and this was because they were dying for food after going back into the nute-free soil and being flushed with 2L.
Anyway, I guess the point of this post is for anyone in my position to just be really careful about how you diagnose your plants and mainly WITH WATERING. I'm quite sure the strong-nute soil started all of this, but I made it spiral out of control briefly by trying to flush etc. and then over-watering in my attempt to bring them back to life. I think it all could have been avoided had I watered more carefully and realised the deficiencies earlier!! Let this be a lesson to anyone in my position. Patience is the key!