What is this?

My plants are about a week into flowering, however this problem has been progressively getting more symptomatic since before flowering. Anyway, the new growth is curling up, almost turning white/light green/yellow. I fed Age Old bloom nutrients 2 days ago, with about 7.0 PH and it has yet to change its trajectory to good health. Any thoughts?
Additionally, there has abeen a slight browning on the tips and cerated edges of the main fan leaves a bit below. I don't know if these problems are related.
here are the pics. Any suggestions help.

*5 gallon
*FFOF and Age old grow and bloom
*Phd water (7.0) slightly high to offset soil acidity (at least it has worked well for all my other plants)

Pretty sure its not heat or light burn, the plant is like 5 feet away from the HPS 1000W and the canopys like 78F.

moisture stress?

That cuping is a sign of heat stress
and the brown tips are useuly a sign of nute burn

Its still hard to diagnose from a couple pics

Check your soils PH and see what your PPM run off of the soil is it will help narrow it down

It does resemble heat stress, if this is happening at only the top 10% of the leaves then if it were me I would be thinking heat issues. If you have a fan blowing air between the light and canopy you can cook them with hot air, especially on an open 1000w HPS. If you do have a fan try not to let it blow air towards the lamp, it tends to do the opposite of what we would think.

GV.

If that's not heat stress I have no idea what it could be... did you say your room temp was 78°?