LED/Coir Fastbud grow - not sure if I'm having problems.

My fem fast buds are 3-4 weeks old, seem a little small to me but they just started producing pistils so it seems like theyre the right height for their life cycle to me. Whats worrying me is theyre a bit pale, and there is some yellowing. I use an advanced LED 100 watt, in coir, watered with ph 5.8 RO water + 1/4 strength FF Grow big with calmag, and last feeding I gave them 1/4 strength FF big bloom. Heres an album of some pics: http://imgur.com/a/aSuAL

i dont know much about growing in coir, but it does look like a nitrogen defficiency, but you should get some advice from a coir grower about how to go about correcting that problem. Id say just giv em some grow feed, but that might not be the solution (if you excuse the pun) gd luck

I've only read a couple coir guide, not an actual grower, but did you only use that chunky coir? looks like landscaping coco, I think you are suppose to use the smaller stuff.

Maybe that's the problem?

just trying to give you some advice with my limited knowledge

Ok, I looked.. I tell so many people with leaves that are yellowing that they need magnesium.. In other words.. Take a small pinch of epson salt and I mean small and put it in with the water.. They will green right up bro!! BTW.. Love the set up!!