Help with my C99 clones

[DVM]

I’m just finishing week 4 since the flip and I have had a few issues with my clones, the mothers are in the same flower room, same everything and they are doing great

My setup:

Two Optic 6 600W (true watts) lights

50/50 Coco/Perlite in autopots.

Advanced Nutrients pH Perfect Sensi Bloom (A&B at 2mL/L) + BigBud (at 2ml/L) + Cal-Mag (at 2ml/L) for a total of 1250ppm and a pH of 5.8-6.0 (the reservoir drifts up over a few days). I checked the pH in the Autopot trays at lights out this morning and it was 5.8

Temps are min 20C lights out and max 26C lights on

RH at 40-50% lights on and 60-65% lights off

This is probably the worst affected top, any ideas?

More pics and some history in my grow log

C99 into flower

I’ve been vegging 3 Cinderella 99 for a couple of months, Christmas eve I made 9 clones from the top of the plants and started training the rest in the manifold style. They go into flower next week so it’s time to do some sorting out [IMG_2204.HEIC] The clones were topped a couple of weeks ago to encourage the side branches, now I’m going to give them a deep topping to get an even canopy of 4-8 branches. Before: [IMG_2208.HEIC] After: [IMG_2209.HEIC] Top down: [IMG_2238.HEIC] The tr…

[Dbpooper]

Almost looks like iron deficiency, I’m no expert by any means so take this with a grain of salt.

[TommyBahama]

It’s not iron deficiency. That starts out yellow toward the center, then spreads outward. Here is an example:

What I see in your photo could be a potassium deficiency, but I’m betting it’s more likely light burn. Are you seeing this issue just at the top of your plants? If so, try moving the lights further away or dimming them.

[DVM]

I’m thinking it may be a combination of the two.

[MidwestGuy]

Can you share a pic of the whole plant? It’s difficult to distinguish what it might be with a pic isolated to one of the tops.

These may be helpful.

[RetiredShenanigans]

Thank you for those two charts.

[DVM]

Sure, lights on in about 4 hours and I’ll get some then

[DVM]

This is the same plant from my original post

You’ve seen the top most cola, this is a lower one (same plant)

This is a different clone

I checked the pH in the reservoir (5.9) and the trays (5.8) at lights on so I think that’s fine. I also moved my lights up almost as high as they will go.