Day 18 of flowering

On some of my taller plants I am showing curling under of leaves and slower growth, it seems to be dictated by size at this point. I assume it is P and K def. but am unsure.
I am using CF's 6 65watt dropped between plants in a 4x4ft the taller plants are level now with the tops of the CF bulbs. The reason this is posted is the concern it is a heat or light height issue. I have checked the canopy temp and it stays at about 78, but the temp seems much warmer to the back of my hand....never uncomfortable.
The thing that confuses me is that several shorter plants are looking much better (actually great) and not slowing down in production. In fact the taller plants look better at the shorter level with more production, so this is effecting the tops and different plants are showing the same curling as they reach this heighth, not all, it is dictated also by the flower production, taller plants with fewer flowers are not showing signs.
I introduced the bloom formula slowly 1.5-4-5 and has received feedings at every watering since bloom 1st at 1/3 recommended dose 2nd and 3rd at 1/2 dose and the last 4rth feeding at full dose 1oz per gallon. I also used pyrosol and 1/4tsp epson on the last feeding. This might seem like to much and I have overfed but as I said the smaller plants are showing no ill signs including those producing lots of flower and those producing little. Because this is dictated by heighth and the amount of flowering, I can only assume it is under rather than overfeeding. I will gather pics and post on my next post. Suggestions until then are much appreciated!