Help: strange leaf yellowing lesions

[angelass]

Thought this was cal mag or zinc deficiency, possibly caused by PH flux to ~5.4 of so. Can't seem to get on track. Very strange... the problem seems to be “”traveling” from 1plant to another – one gets spanked and as it seems to recover slightly another seems to exhibit worsening symptoms. New growth looking SAD. Guidance Please...

Dr Kripp - Melon Kali (Sat Dominant)
5 weeks veg, FF soil & nutes (light) + recharge, silic & Cmag as needed, 7 gal cloth pots
Fluence Spydr LED @~80% , ~22/2 , CO2 ~800
Temp Range 69 – 83 (avg 80)
RH Range 52 – 79 (avg 72)
PH Soil 6.2 – 6.6. HOWEVER – for some strange reason PH seemed to flux dramatically in all the pots a week or so ago, down to 5.5 (may )
No Pests Identified. HOWEVER I did not sterilize tent after last run???
Watering 1-2 x weekly, HOWEVER not drinking much at all

 

[RichieRich6988]

This might help

 

[angelass]

Thanks Richie - Update...

Recovering slowly. I musta FU'd a feed, PH settled between 4.5 & 5 in all pots . Watered with Hydrated Lime ~a week ago and now the PH's seem to settle ~ 5.8-6. Will water with 7.0 next and hopefully get a boost within healthy range. Still not drinking though, wish I can expedite drying out the medium. Any ideas on that welcome. Worse case I'll transplant, however 7 gal pot are a bear to do so and I prefer not. Hopefully they'll be ready for a healthy 12/12 regime within the next 10 days, I have a perpetual and don't want to mess up the timing/routine.

Still don't know what specific nute deficit manifested - probably a combo of multiple challenges. Lesson relearned, "PH is paramount"

Thanks again

 

[Booja]

I had the same problem showing up on my first ever grow (still in progress). I figured it was a ph problem and flushed heavily with neutral water and the problem went away. My grow is in coco/peralite so flushing was easy.

All of the effected leaves on my plants eventually skeletonized and died but the plants survived.

 

[RichieRich6988]

Thanks Richie - Update...

Recovering slowly. I musta FU'd a feed, PH settled between 4.5 & 5 in all pots . Watered with Hydrated Lime ~a week ago and now the PH's seem to settle ~ 5.8-6. Will water with 7.0 next and hopefully get a boost within healthy range. Still not drinking though, wish I can expedite drying out the medium. Any ideas on that welcome. Worse case I'll transplant, however 7 gal pot are a bear to do so and I prefer not. Hopefully they'll be ready for a healthy 12/12 regime within the next 10 days, I have a perpetual and don't want to mess up the timing/routine.

Still don't know what specific nute deficit manifested - probably a combo of multiple challenges. Lesson relearned, "PH is paramount"

Thanks again

You definately want to flush them before you change nutes. An east calculation for flushing is use double the PHed water of the size of the pot. Then you will want to use both flower and veg nutes at half strength together for the first week of 12/12 after that you can got to straight flower nutes. And Yes PH is sooooo important in all stages.