Growing Pains

Hi Guys,

I'm new to all of this so please forgive my ignorance. Any help or advice would be greatly appreciated.

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The leaves of my first plant (first two pictures) look crinkly with slight nute burn ( I think that's what it is).
The second plant has two leaves at the bottom which have yellow-ish discolorations (following two pictures)

The third plants all look healthy, at least to me.
The fourth plant looks healthy but also with slight nute burns (last two pictures)

Including these problems I've identified, are there any other problems identifiable that I've missed that some of you expert growers can spot?
Also, any solutions/advice regarding the current problems/future identified ones would again be greatly appreciated!

They look great. First plant looks like it could be a mutation, nothing to worry about at this time either way.

So far so good. Just keep the ph on point, or close.

Hello, look at the first pics, do you see how deep the grove's on the sides of your leaves?
that mean the plant is trying to cool down, vent your room out, IMO it looks like it may be too hot in your grow.
all in all they look good except for that. but it is easy fix.
Good Luck..