First Grow (COCO) 1 out of 6 strains not playing ball

Hello All,

long time reader, first time poster.

So i was hoping to get one grow under my belt before i came online and id my own journal but alas im having issues that i cannot get on top of for the life of me.

Ok a little background

Medium - COCO
Grow - INDOORS
Nutirents - General Hydroponic and CalMag ( runnin approx 500ppm)
Lighting - 140w CFL for veg and 1600W mars hydro LED for flower
Temps - 83 constant when lights on 72 when lights off
Humidity - 50% lights on 60% lights off
Schedule - Regular PH'd water in morning and Nutrients to 20% run off at night.
Method - SCROG/LST/TOPPING

PLANTS with issue 2 x Bubblegums ( week 3.5 flower)

SAME age plants with NO issues on same feeding schedule 0 1 x Currant Kush, Arjans Haze number1 and some autos

ALso have two autos in there a few week ahead of there sisters

Tale of the Tape

• Noticed yellow tips on leaves two weeks ago ( assumed it was light burn and lifted lights an additional foot)
• A few days later yellow tips were getting more pronounced (thought nute burn, ran half strength nutes for a week)
• Tips started looking "rusted" see pics
• I flushed with just P'Hd water 10-x the pots holding capacity
• began regular nutes the following day
• This is just starting to happen on the second bubble gum and has smaller rusted tips

from what i have read i may have MG deficiency, phosphorous or Zinc ??

Thank You community all the help!

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Hey guys, so after talking to a few buddies IRL they have all come to the consensus that the issue here is Phosphorous deficiency. Somtimes the same kinda problem can also be MG deficiency but since im already using CalMAg with all feedings the issue is leading towards P.

Now i am only having this issue with one strain the others are running smoothly on the same feed mix. I will add additional BLOOM from the GH flora series just for the two bubblegum's. this has a high MG/P/Potash count.

I will report back with results !

 

Hey TWW, thanks for your thoughts! when the lights come on i will take a better photos of the affected bubblegum and her sister which is starting to show the same signs as the first. I did get at P additive and have done one feeding with it only to the bubblegums.

If it were nuteburn would i not be experiencing these rusted brown tips that spread up the leaf? I have yellow tips on some plants, this i assumed was nuteburn.

oh i use a PH and TDS meter prior to each watering, PH between 5.8 and 6.0 and my PPMS are 500