Can someone help

I have a total of 6 plants two different strains four of them are grandpa‘s cookies 2 are double cherry indigo I am running bush Dr. Coco loco 3 gallon pots using Athena nutrients and this is my first time using LEDs temps are between 68 and 72. Can somebody give me some input on what is wrong only two plants are doing this the leaves are turning yellow from the outside in I was told I wasn’t adding enough Cal mag so I bumped it up and the problem is still there. Any advice is always appreciated thank you in advance

It's too cold and the humidity is probably a little too low.
I would add a heater and humidifier if you don't have one and put them on an inkbird dual controller. Then give them a foliar spray with epsom salts. I would also move them to larger containers. But that's me.
Good luck friend

The yellowing is there to stay, you just wanna make sure it doesn't continue working its way back into the leaf. Keep an eye on it to make sure it doesn't further progress.

I would also flower those as soon as you can get them straightened out. You are getting short on space.

I agree with Jimmi, raise temps first and foremost. See if you can get it up to 80 deg at leaf level-that alone might fix the issue. Also, what PPMs are you running now, and how often? When you feed, you should feed to plenty of runoff to keep the salts from building up.

Rurumo said:

I agree with Jimmi, raise temps first and foremost. See if you can get it up to 80 deg at leaf level-that alone might fix the issue. Also, what PPMs are you running now, and how often? When you feed, you should feed to plenty of runoff to keep the salts from building up.

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I have them in a 4 x 8 tent in my basement I have a space heater in there set at 71° I split a gallon of water between all six every other day and I have been measuring the EC and it has been 1.4

I would get that tent up to 84f and lift the pots further off the floor

youngwun11 said:

I have them in a 4 x 8 tent in my basement I have a space heater in there set at 71° I split a gallon of water between all six every other day and I have been measuring the EC and it has been 1.4

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Potassium deficiency. Check the internet if necessary.

I'm pretty sure what you got going on there is early toxic salts buildup. Kind of like nute burn in slow motion from an overabundance of nutes over time being stored in the leaves until it becomes toxic. Radiant energy from the lights is causing temps in the upper leaves to build up so those leaves transpire more water in an attempt to keep cooler drawing more nutrient salts in that stay after the water evaporates. Because your overall temps are low it manifests first in those that have the highest heat levels rather than in the oldest fan leaves down lower first. The yellowing will progress and the edges start browning soon until the leaves go yellow/brown all over and become thick and crispy.

You can't repair the damage being done but either flush lightly to reduce the levels of nutes in the pots or just give plain water for a bit so the plants are forced to use stored nutes and reduce the salts trapped in the leaf tissue to slow the progression. Flipping them to flower would help use up those nutes as the plants feed heavily during the stretch period while they go thru a big growth spurt. Go easy on any bloom nutes as they already have plenty of stored mobile nutrients like NPK.

youngwun11 said:

I split a gallon of water between all six every other day and I have been measuring the EC and it has been 1.4

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That is not the best way to water your plants in either soil, soilless or in your case coco. You need to saturate the pots and with coco not let them dry out. 1gal between 6 pots is nowhere's near enough.

For the sake of argument this is what low K should look like.



Good luck.

Ph and ec of runoff. Always check these first when having problems. If ph is off nothing will work correctly.

OneMoreRip said:

Ph and ec of runoff. Always check these first when having problems. If ph is off nothing will work correctly.

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And you actually believe that just getting runoff and checking it is accurate?

How would you prepare to get the most accurate readings possible?

Even an accurate ppm reading needs prep.

OldMedUser said:

And you actually believe that just getting runoff and checking it is accurate?

How would you prepare to get the most accurate readings possible?

Even an accurate ppm reading needs prep.

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not sure what you mean but it has worked for me, to get an idea as to what is going on in my medium. accurate enough, just water till run off, catch the run off in a cup and test it. If something is off, you should be able to tell pretty easily.

I have stuck normal ph cheap pens in moist-weter soil and get better readings, faster, then with my bluelab soil ph pen. Wouln't suprise me if you could do the same with ec pen. I just haven't done that enough to recommend it.

also comparing my ec run off to ec soil pen says testing runoff is pretty accurate

@ op, you shouldn't need any additives to a general fertilizer/nute, from my experience. just one bottle of 2-1-2 or close to it, start to finish

i've had a lot of problems and always ppm/ec or ph is the cause