weird deficiency? any guesses?

Ok so I've been growing this same strain for awhile now with no problems. Although I do believe the new growth on the clones are showing signs of me giving too much nutrients too soon. But the real question is what kind of deficiency is this on the lower fan? I've looked and looked with no luck. Any help would be appreciated.

Grow medium: pro mix

Nutrients: GO full line

Feeding schedule: half strength nutes mixed in one gallon split between 8 2 week old cuts. I stick to the recommended strength for GO line.

Light: t5 8 bulb 4ft.
24hr light.

5 gallon pots.

They have only had one nute feeding since being transplanted. Fed on only water for first 10 days.

No bugs at all temp stays at 71°.

They look fine. Clones get curled leaves sometimes. No biggie. The yellowing tops could mean that you need to feed them. Dont freak out, they look fine.

Yup, it just looks like a small mutation, I wouldn't worry about it.

Cool. Thanks for the help guys. Kinda what I was thinking as well on the mutation. Had a buddy that grows say something about salt/calcium build up? But I wouldn't have that problem with organics right? The plant I took the cuts from had a few deformed leaves as well. But I don't remember seeing any of them before I took clones while I was at day 15 in flower last run.. possibly the answer there..

My plants do the same. I think its strain specific.