Curling leaves - young plant?

Hi,

Need some help determining what the issue is here. Ph is 5.9-6.1, seems the plant on the left has slight yellowing in middle of main leaves, cotlydons are not yellowing much so shouldn't need nutrients yet right? Only using purified water at pH of 6.0 at the moment. No nutrients, under HPS 400w and also Metal halide 400w - Could it be heat? It is roughly 85 degrees farenheit on average? Please help. Roughly 2 weeks old, in rockwool cubes.
Any other info needed I can easily provide.

Many thanks,

Rockwool.

Forgot to mention I water every other day, not vast amounts as they are seedlings... Enough to just about saturate

Every other day? STOP watering! give them time to breath, your drowning the poor things

Right, also... There seems to be some grey spots on the first pair of leaves (not the cotyldons) on both plants? The one on the right has it right on the tips and the one on left is hard to see but some small patches.. I've had a look and managed to find nothing about grey spots? What does this indication mean?

Many thanks Nomads.

You have 800w of hid over that little thing? Bro you only need a cfl at this stage, or a 150w mh at most. Because you have cooked it with high light intensity it it very sick and now diseased, stop overwatering ,back off on the lights and hope it recovers, which is very doubtful.

The thing is buds, it had greyness and curling prior when I had them under the 3 CFLs... Surely it would be okay? It doesn't seem to be crisping up but more of a grey colour? Almost like nute burn but I haven't even nuted yet?