Late flowering bud leaves turning yellow?

[GTC]

Problem: I had an issue with an uncalibrated ph pen several weeks back which ended up making a bunch of leaves spotted and deficient. I since got a new ph pen and fixed the pH issues. Over the last three weeks, the leaves stayed the same but she kept growing bigger and bigger buds so I figured everything was okay.
Now, she’s starting to get yellow bud leaves.

Medium/grow method: rdwc

Feed and supplements used: Using attached nute schedule. Had to dilute the mid flower ec to <1.4 because it was burning but wk 10-11 is being run as-is (~1.2ec). Today was the first time ph went down (5.5) when I checked so I added only water to dilute and adjusted the pH back to 5.8. It’s at about 0.8-0.9 ec now. She's drinking plenty of water daily with stable ec and generally slow rising pH.

Water source: RO water w/ CalMag+ and H2O2.

Strain and age: FastBuds Strawberry Pie, wk 11

Climate: Res at 68-70, rh at 50%, tent at 78. Trichs are still glassy. Roots are in perfect condition.

Light used: Mars ts1000 supplemented w/ 2x 40w ebay light bars added mid-flower. 18/6 schedule

This doesn't appear normal, what corrective action should I take?
One of the larger/higher colas has a bud at the top appears to be opening up and "blooming" with much lighter colored material. what is this?? (I'll take pic of this later if needed)
Any clue on how much longer until harvest?

Thanks!

 

[Mañ'O'Green]

You are still seeing the PH damage showing up. I totally killed a crop under the same bad meter scenario. Not too much you can do now because the plant is close to done.

You should only use H²O² in a sterile DWC grow. I have tried sterile and it was lousy compared to using Botinicare HydroGuard for pathogen control.

I have found that EC 1.0 or ~500 PPM to be the sweet spot for Auto Flowering plants.

The sudden bud growth probably stems for the nutrients being available at the proper PH again.

Just keep any eye on the trichomes she is almost done.

 

[GTC]

No more sudden/extensive pH damage, just a slow yellowing of leaves in the upper areas. Just looks like slow leaf death but the buds are doing fine and lower leaves are remaining green. pH is correct now and tested daily w/ my new Apera meter and every few days w/ dye solution.

This is a sterile grow.

I didn't start having issues until pushing nutes past ec 1.2 once it hit flowering (most guides say they need more nutes in flower so that's what I did).

There's a bunch of larf and popcorn too. Planning on making butter with them. Can I cut the tops and let the rest of it go few a few more days to ripen up? or is this not really worth it?