Purple and yellow leaves in flower; deficiency?

I’ve tried researching several forums, but still don’t know what to do. Both the fan & sugar leaves on my Amnesia Haze Auto are turning dark purple and yellow. This is at TOP of the plant so thinking it might be an immobile nutrient? LED light was about 17" so raised to around 22". Temps never drop below 65F so don’t think it is due it being too cold.

Ticket info below but key points are that measured runoff PH is usually between 6.5 and 6.7; last runoff PPM was 759 so what gives? You all think it is a nutrient issue or something else? Maybe Phosphorous deficiency? I’m using Fox Farms tiger bloom at 5ml per gallon every other watering so maybe once a week. Was using 5ml of CalMag too but lowered that to 2.5ml thinking there may be a lockout.

I have another AMH at same stage and no purpling at all so don’t think it is genetics. Plant is 68 days from sprout and in 4th week of flowering. Thanks for any help! This is my first ever grow.

Amnesia Haze Auto from IloveGM
Method: Fox Farm Ocean Forest Soil
Vessels: 5 Gallon fabric pot
PH of Reverse Osmosis water going in is 6.6/ Run off = 6.5 to 6.7
PPM/TDS = 767
Indoor = 4x4 grow tent in garage
Light system = 2 ES 300 LED’s at 100%
Temps; Day = 75F; Night = 65F
Humidity; Day = 53%, Night 45%
Ventilation system; 6" Cloudline exahust fan + 12" oscillating fan on wall
Co2 = No

Pic under LED lights today

3/24 under natural light

3/24 I believe the lower yellow fan leaves are just the plant using them up and not N deficiency


Looks like classic nitrogen deficiency. You say you are giving Tiger Bloom but no Grow Big? You’re supposed to using Grow Big (along with Tiger Bloom and Big Bloom) for your nitrogen til past week 5 of flowering.

No need to adjust the PH of just plain RO water as it won’t affect the soil PH…nothing in there unlike tap water or well water. That’s assuming your RO is working correctly…ie check its PPM to make sure it’s doing it’s job.
When you add nutrients to the RO water that’s when you need to check PH and adjust if needed.

@Hellraiser checked my grow log and I stopped using Grow Big on 3/13. I agree that it looks like textbook nitrogen deficiency so I just fed it 5ml Grow Big and some calmag. Runoff was 868 and PH 6.3 so will see how she reacts.

@Skydiver In terms of PH’ g RO water yes I only adjust when I feed. I tested PPM of my RO and it looks good at 12, but PH is 8.9. I thought RO was supposed to be 7?

RO and distilled water don’t have enough ppm to hold any real PH, the readout for them is pretty much meaningless. When I do water only and I want the water to actually hold a PH, I will use 1/4 tap water with the RO and then ph adjust.

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