Is 60 degrees at night cold enough to lockout Phosphorus?

So my leaves started purpling about 10 days ago, posted some threads trying figure out the problem, you may have seen them. I have 2 ton senville air conditioner in the room, 4 1000w lights going not air cooled. Well I noticed somehow the AC got switched to Cool mode, as opposed to Auto where it heats when the temp drops. I went in the room about 5 hours after lights out and the room was 60 degrees with the AC running. So im wondering is 60 degrees at night is cold enough to make the plant not take Phosphorus up causing the purpling? Or is it more likely something else is going on inhibiting the uptake of P. Growing organic in Roots 707 soil, have given them compost tea and great white myco and when the purpling showed up beginning of week 4 flower I gave them some roots organics nutes once at 1/4 strength and then 2 waterings later at 3/4 strength. and the purpling increased after that. was it just too cold?

Lower temps will cause purpling in a lot of strains. Nothing to worry about if it was just one night.

Strain would be needed to even think about help. In the outdoors it's regular for temps to drop below 60. I've understood a good range for night temps is 15 degrees below your day temps to imitate nature.

jimmer6577 said:

Strain would be needed to even think about help. In the outdoors it's regular for temps to drop below 60. I've understood a good range for night temps is 15 degrees below your day temps to imitate nature.

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half the room is Original OGK and half the room is Afgoo. Ive had both these strains for almost 2 years now and they don't naturally purple like this. I did just read a thread that showed pictures for P deficiency during veg, P deficiency during flower, and P deficiency from cold temperatures and the purpling in the leaves looked exactly like whats going on in my room. I also tested the soil with the rapitest kit for N,P,K and it showed theirs plenty of P in the soil. Its definitely being locked out, I tested the ph of the soil and it varied as could be expected with organics. The first time it looked a darker green like around 7.7, then the rest of them looked like 7 on the dot. Plus with organics and the microbes and what not I figure the soil should buffer the ph itself. So now im left with was it too cold. I know ive read below 50 degrees locks it out. As far as outdoor I would imagine you still get huge buds even with cold nights because you have the sun for light which provides for a heck of a lot more photosynthesis to take place than with indoor lights, even being 1000w.

MammothGrow said:

half the room is Original OGK and half the room is Afgoo. Ive had both these strains for almost 2 years now and they don't naturally purple like this. I did just read a thread that showed pictures for P deficiency during veg, P deficiency during flower, and P deficiency from cold temperatures and the purpling in the leaves looked exactly like whats going on in my room. I also tested the soil with the rapitest kit for N,P,K and it showed theirs plenty of P in the soil. Its definitely being locked out, I tested the ph of the soil and it varied as could be expected with organics. The first time it looked a darker green like around 7.7, then the rest of them looked like 7 on the dot. Plus with organics and the microbes and what not I figure the soil should buffer the ph itself. So now im left with was it too cold. I know ive read below 50 degrees locks it out. As far as outdoor I would imagine you still get huge buds even with cold nights because you have the sun for light which provides for a heck of a lot more photosynthesis to take place than with indoor lights, even being 1000w.

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"and P deficiency from cold temperatures and the purpling in the leaves looked exactly like whats going on in my room." the picture from cold temps looked the same, not the other other 2 pics

jimmer6577 said:

Strain would be needed to even think about help.

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MammothGrow said:

"and P deficiency from cold temperatures and the purpling in the leaves looked exactly like whats going on in my room." the picture from cold temps looked the same, not the other other 2 pics

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Maybe look into silica, it will help with the plants P uptake. You have a very interesting situation. I keep my room between 57-60 at lights out due to heating cost without any coloring.

I've heard many kushes love a slightly warmer temp. People tend to run the temp at 84F lights on instead of 75-78F, so I assume the cold tolerance is similarly adjusted. A 5F-10F bump if possible, would probably show well in the plants.

Kush Knight said:

I've head many kushes love a slightly warmer temp. People tend to run the temp at 84F lights on instead of 75-78F, so I assume the cold tolerance is similarly adjusted. A 5F-10F bump if possible, would probably show well in the plants.

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My OGs have seen temp spikes of 88-90F when my cold-air humidifier runs out of water and I forget to refill it. Even that doesn't seem to bother them for a couple hours...

jimmer6577 said:

Strain would be needed to even think about help. In the outdoors it's regular for temps to drop below 60. I've understood a good range for night temps is 15 degrees below your day temps to imitate nature.

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Good advice......
correct about the outdoors (-btw, thats not strain but grow conditions you basically were saying was important) and simulating day cycles (-that means temp and light, and if you're feeling fancy, rh has to be adjusted throughout the day).....
But why the hell would you need strain info to give any advice? Do you have experience with 100's of strains? Doubt it.
It helps, but is not at all necessary in this case.

It's stated that 60F is the lowest you should ever allow the room to get at night. In reality, that means many strains see ~63F and lower as a minor stressor, with results shown in different ways. As such the answer is yes, temp could be the issue.

Therefore, I CAN think of help, without strain info.

Kush Knight said:

Good advice......
correct about the outdoors (-btw, thats not strain but grow conditions you basically were saying was important) and simulating day cycles (-that means temp and light, and if you're feeling fancy, rh has to be adjusted throughout the day).....
But why the hell would you need strain info to give any advice? Do you have experience with 100's of strains? Doubt it.
It helps, but is not at all necessary in this case.

It's stated that 60F is the lowest you should ever allow the room to get at night. In reality, that means many strains see ~63F and lower as a minor stressor, with results shown in different ways. As such the answer is yes, temp could be the issue.

Therefore, I CAN think of help, without strain info.

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I run 4-5 strains that turn purple naturally. I know of a lot more and was wanting to make sure he wasn't running one of them first. If it was his first run with these strains then it could have been very easily just the strain turning purple naturally. But hey, I don't want to give bad advice by assuming things. I would rather have you call me out for asking what I believe to be a reasonable question before answering it with wrong info. But what do I know, a plant naturally turning purple whoever heard of such a thing.

we grew without AC this summer with 0 problems.. nice dense fat yielding buds.. love it . . first year i didnt use AC.. just direct outside air..threw a hepa filter.. into my room lights on at night. works amazing for me.. loved it.. didnt have to waste mad money on AC.

jimmer6577 said:

I run 4-5 strains that turn purple naturally. I know of a lot more and was wanting to make sure he wasn't running one of them first. If it was his first run with these strains then it could have been very easily just the strain turning purple naturally. But hey, I don't want to give bad advice by assuming things. I would rather have you call me out for asking what I believe to be a reasonable question before answering it with wrong info. But what do I know, a plant naturally turning purple whoever heard of such a thing.

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Good enough for me... But so you know, strain is often the least important factor. Cannabis as a Genus has general growing properties, so as long as you stay in the limits, any good strain should have almost no problems. Only really bad (or rather unrealistic i.e. some sort of french bred sativa crossed with a mysterious landrace alaskan auto containing rather pure ruderalis) genetics tend to be uber-finicky.

Kush Knight said:

Good enough for me... But so you know, strain is often the least important factor. Cannabis as a Genus has general growing properties, so as long as you stay in the limits, any good strain should have almost no problems. Only really bad (or rather unrealistic i.e. some sort of french bred sativa crossed with a mysterious landrace alaskan auto containing rather pure ruderalis) genetics tend to be uber-finicky.

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Have you ever ran a real multi strain grow and try to treat every strain exactly the same? Some strains are more mold resistance,some are more bug resistance, some are more prone to hermie (in some this goes away with clones ex.OG), some stains turn purple, Some strains like heavy feeding some lite feedings. I have grown over 100 different strains and can tell you they all like things just a little different. It does have general growing principles as a plant in a whole, but each strain has more specific requirements. Spend some time on researching true landrace strains and compare where they come from and you will see that they grow in completely different environments. And if he was running a purple strain we wouldn't have had this conversation, but wait, all he said it was turning purple and never mentioned the strain. If he was running grape stomper or something all of the advice would have been wrong because the plant would have been doing as it was supposed to do. If you call a mechanic, the first thing he asks is what type of car, but hey they all have tires, gas, and a motor why would the type make a difference, they all run of the same general principles.