Leaves turning yellow (pics included)

Setup: 400W HPS
DWC
2nd month into flowering
Holland's secret nutrients

Any idea what could cause the leaves to turn like that?

looks like maybe a heat thing..where did the problem start at the tops, everywhere or at the bottoms

Can i see the whole plant please ? See what the rest of it looks like.

take a pic of plant it could help u out more

How close is your light to your plants?
Could just be the plant killing off the lower leaves for neuts.
Looks like heat damage tho

Pics of leaves don't mean shit, please post plant pictures.