depends on the strain, if its indica, itll stay nodal and stalky so 3000k would be better than 6500k but it all depends on how much headroom you have, I like using 3000k so I dont have to clip a BUNCH of nodes before flip. its up to you :)
this was at 6ft camera level. my rdwcs are the sour diesel plants in the back starting at the red light back to the wall. had 4 of them. 6ft 5 inches. had about 8 -12 main colas each, my coco white cookies below.
oh, right. I'm thinking there is too much K in your coco. coco retains it well and usually coco formulas have a little less than normal. i totally forgot lol
roots is pretty neutral, if you use it make sure you throw in some ocean forest from FF about half and half. as well as 30% extra perlite and some dolomite lime to keep ph stable.