Possible Magnesium deficiency in Coco or PH?

[Rocket Soul]

Looks more like a potassium deficiency to me.

Im not great with nutes signs but id lean that way aswell. Mg locks out potasium.

But more importantly those plants are not transpiring properly; saggy leaves. Whats environment like? Get those leaves stretching out first then adjust nutes. low transpiration (OP: youre under led lights, right?) can cause all sorts of nute signs which are better corrected thru healthy drinking and transpiration.

 

[oaktree]

Im not great with nutes signs but id lean that way aswell. Mg locks out potasium.

But more importantly those plants are not transpiring properly; saggy leaves. Whats environment like? Get those leaves stretching out first then adjust nutes. low transpiration (OP: youre under led lights, right?) can cause all sorts of nute signs which are better corrected thru healthy drinking and transpiration.

100W LED, temps between 74-80 degrees, humidity has been ranging between like 45-65%

 

[oaktree]

Is that a proof test? <5% store in a cool dark place. >5% keep out of reach of children.

The pH meter calibration solutions can be useless, or become useless quite quickly. I have seen posts from people comparing lots, and tracked my own mixed from salts. I have nothing good to say.

It's in the yellow.
Close enough.

It's a General Hydroponics PH Test kit. I think maybe 2 less drops of PH down would get me to a pretty good spot.

 

[Rocket Soul]

100W LED, temps between 74-80 degrees, humidity has been ranging between like 45-65%

Led lights dont carry any infra red which heats the leaves so you generally have to work a bit more with your environment to get the plant to drink. Id recommend to raise the temps a little bit to start with and see what happens.
But its really hard to make hard predictions cause if what youre seeing is K lockout increased transpiration may make it worse and using well water is a bit unpredictable. Do you measure your EC? How much is base EC and how much is nutes?

 

[Ca++]

It all depends on how you use and store the solutions and how they're being made. I've use the same pH 7.0 solution for well over a year.

The problem is if you decide to re-use the same solution or put it back in the bottle or if you use any DIY solutions without proper preservatives. pH calibration solution is for single time use and calibration only.

Indeed. The little sachets of powder make 250ml of solution. You use about 25ml to set the meter, and the rest just to wash it before going in the test solution. I have been meaning to make it up stronger, to see if it remains more stable. I have been really clean about it, and the 10 grows seams of snot through it. It itself seems dirty. The 4 went visibly bad to. I have to look at preservatives, but I know what I have isn't a good pH. Perhaps less water will make a better buffered solution, that can handle a little preservative. I have really not looked

The 7s seem to last the longest.

 

[oaktree]

Led lights dont carry any infra red which heats the leaves so you generally have to work a bit more with your environment to get the plant to drink. Id recommend to raise the temps a little bit to start with and see what happens.
But its really hard to make hard predictions cause if what youre seeing is K lockout increased transpiration may make it worse and using well water is a bit unpredictable. Do you measure your EC? How much is base EC and how much is nutes?

I have not been measuring my EC. I do have a cheap meter which I'll use to check and report back.
I'm going to replace my reservoir with the unsoftened water and PH'd nutrient solution based off of the PH test drops and then give it a few days to see how the plant reacts to that. The temps are usually in the upper 70's to 80 degrees. I may have to adjust the automated duct fan to keep temps in that upper zone.