Photoperiod Odd coloured patches on plant with a history of problems

[Idiot-sativant]

So I overwatered in Veg, dealt with Nitrogen toxicity in Veg, and now that it seemed to recover and has been flowering a few weeks I'm getting this curious leaf colour. It makes patches or along the rim/edge of the leaf.

We've had a week of -25C/-13F weather(and a greedy bastard landlord) making inside 15C/60F with lights out. I'm only familiar with heat damage, does this look like a cold issue? if not maybe I haven't addressed the previous issues enough yet. The issue is worst with my Blue Cheese seen below.

Soil: Promix Organic Veg/Herb
Nutrients: General Organics
Tap water 8.5, Ph down to 6.5
Day Temp: 23.5(74.5)
Night Temp: 15.5(60)

 

[namvet25]

Need pic with natural light

 

[Waira]

that's cool enough to stall out nutrient uptake and transport, along with growth in general; it also tends to bring out colors in some plants which may express such colors naturally,... As a weak diagnostic symptom, the purple petioles and burnishing can be signs of mild P defc., but because of the common variable color expression in many strains, it's not usually definitive, though it follows here,...
Organics are milder and usually slower acting; the soil microbes need time to work on breaking things down and cycling them, but the coll messes with that as well,... I see some edge browning, might be some K defc. too,... Get us normal light pics, whole plant too please

 

[Idiot-sativant]

Just got back in town, Thanks for the replies! I'll work on taking better pictures outside my tent tonight.

 

[Idiot-sativant]

I have my night temperature up to 18.5C/65F now. Most of the leaves got very purple or yellow over the weekend. The soil is dry and ready for watering and first aid soon. Thanks again everyone.

 

[Eastcoastcultivati0n]

What week of flower are you in? 60 seems pretty cold for nighttime temps, I personally experienced this same issue close to harvest a few grows back when I had some stuff in the basement. Had the same discoloration, I'll see if incan find pics.

 

[Eastcoastcultivati0n]

This was some blue dream. My night time temps were 58-62.

 

[Idiot-sativant]

Day 97, Switched to 12/12 on Dec25th(35 days since switch). My other Blue cheese(Topped) doesn't have this issue although the buds are turning light purple but not the leaves and very little yellowing. This Blue Cheese was LST only.
I had to raise the tent off the floor and run a heater for the cold spell we had.

That looks very similar to mine @Eastcoastcultivati0n. Did your Blue Dream turn out ok in the end? I like the idea of colourful buds but most of my leaves are half dead. The buds look alive and smell good so I have hope it will pull through. I still have a month of flower left according to my plan.

Based on Waira's comment I was considering a heavy feed of CaMg+, BioBud(bud enhancer) for the Potassium/Magnesium looking deficiencies with a light or regular feeding of BioThriveBloom even though the issue looks to be caused by lockout from cold stress. Good/Terrible idea? Just wait and Pray? Suggestions?

 

[STILLSMOKIN]

Day 97, Switched to 12/12 on Dec25th(35 days since switch). My other Blue cheese(Topped) doesn't have this issue although the buds are turning light purple but not the leaves and very little yellowing. This Blue Cheese was LST only.
I had to raise the tent off the floor and run a heater for the cold spell we had.

That looks very similar to mine Eastcoastcultivati0n. Did your Blue Dream turn out ok in the end? I like the idea of colourful buds but most of my leaves are half dead. The buds look alive and smell good so I have hope it will pull through. I still have a month of flower left according to my plan.

Based on Waira's comment I was considering a heavy feed of CaMg+, BioBud(bud enhancer) for the Potassium/Magnesium looking deficiencies with a light or regular feeding of BioThriveBloom even though the issue looks to be caused by lockout from cold stress. Good/Terrible idea? Just wait and Pray? Suggestions?

I would be moving on to straight water. In my experience when leaves turn purple it blocks out the spectrum it needs for photosynthesis. I just can't see more nutes helping anything if it can't process light. But just my opinion.

 

[Waira]

wow! - lovely,.....most of this is normal for the strain mate, a classic end stage color-up boosted by the cool,......indeed, check the trich's now to assess their ripeness stage: clear = immature, cloudy =ripe, amber = past prime, THC degrading into CBN, a very narco-sleepy cannabinoid,....
...warm her up and feed meantime, until she's near ready to harvest; with organics, you don't need to do a long "flush" cycle, if any at all,...

I would be moving on to straight water. In my experience when leaves turn purple it blocks out the spectrum it needs for photosynthesis. I just can't see more nutes helping anything if it can't process light. But just my opinion.

..... this isn't what's happening mate, there's still chlorophyll working in there, and the other color pigments also contribute to photosynthesis,...