Hi @Yvngstonie, I agree that the plant is exhibiting a deficiency in Iron and or Zinc. This is either because those elements are not present in the media, or that the pH of the root zone is too high or too low for the plant to uptake those nutrients.
If it was my plant, I would prepare about 3x the amount of water & nutrients you normally feed, and slowly water all of that in to flush out/clear out the root zone/media. Replacing the water & nutrients that are in there now.
I agree with both answers.
I noticed iron def can also be caused from cold temps. Whats your temps?
I flushed each plant with 3-4 gallons of water at 6.2-6.5 ph (sorta rushing had to take them outside and didnāt want them in sunlight too long rather than my led lights so I donāt fuck with the plant more) and checked the runoff at the end and the ph was like 7.5-8 ph. I canāt seem to get the ph down and I know they are hurting from it. Iām using fox farms nutrients. And I have soil mixed with coco. I have no knowledge of how to fix these issues in a short time basis, they are at the end of veg and I want to get them into flowering but I need to fix this issue.
Temps are between 68-75Ā°F. I k ow thatās not the issue, no other heating or cooling issues, Iāve had them before with this tent and fixed that issue a couple months ago. I am trying to use properly phād water.
Hi @Yvngstonie, I need to apologize for not mentioning that you should pH adjust to 5.8, no lower than 5.7. This will help in lowering the pH (I hope!), I have never used Fox Farms nutrients.
I wonder if any of these knowledgeable and helpful growers can help on lowering Soil (Coco) pH / Fox Farms. @Deanroche, @Stoney1BudTokie, @Graywave, @SJ1, @Bentgenetics, @Wargoat, @anon81552836, @EastMeetsWest
I had something similar, was advised to flush with ph 5.5 water and go from there. You need to go lower than you think to get it to drop.
Iāll tell you what other growers have told me. Itās useless to measure the pH of your runoff. Why? All you need to know is the pH of your inputs and the soil. Really you just need to know soil pH when you amend it. Runoff pH is very inaccurate and trying to adjust it wonāt work in correcting soil pH. You could have a runoff pH reading of 7.8 but the soil could be 6.1. I would recommend getting a pH meter specifically for soil (bluelabs is a good brand) if you think soil pH is the culprit. Flushing was a good move!
FOOP mist is an organic foliar spray that is specifically used for correcting deficiencies quickly. A few members here use it. Hope this helps you 
Hi @Graywave, thanks for the input. I hear you, and I agree with getting a Soil pH metre, but from my personal experience, when I first started, I followed the advice you shared and I had many issues that I was not able to correct or dial in without measuring my run off pH & the PPMs.
Rootzone pH and root zone nutrient PPMs are the only real problem Iāve ever had in the past, both were solved by me measuring the run-off pH & PPMs after every feed. All my grow logs have the feeding and run-off measurements. Since doing this, I have not burnt any tips, nor have my plants experienced nutrient lock out due to high or too low pH in the soil/growing medium.
If I feed 550 PPM nutrients at 6.3 pH and my run-off reads 850 PPM and 7.5 pH, I know I have a problem, and I will see my plants yellowing if I do nothing.
Personally: If I am watering from the top down, using any growing media/medium I would measure pH until I;ve done at least 5-6 successful grows, then it would be reflex/intuition/a pattern will emerge.
Just realizing that what @Graywave is saying here, I would agree with when I have an organic no-till Living Soil, with healthy microbes, fungi, worms, etc. to balance the pH for their needs, and therefore feed the plant.
Sorry for making 2 post on this 
I donāt even check soil Ph, so my solution has been covered. Which is to flush with Ph corrected water with your normal nutes. Not the case here but it if had burnt leave you would flush with Ph corrected water no or reduced strength nutes
When I first went to soil from hydro I would check the run off but it just led to me chasing it and the plant wasnāt thrilled so I stopped. I just make sure itās right going in and it takes care of itself.
Thatās also how I would set it going from dry coco bricks to my final amended mix, in my case itās pretty basic. I saw what you said in your last post as well. Still IMO something is off going in most likely. I had a Ph meter that was off and something similar happened to me once. Not saying that is whatās happening but stuff like that can does happen.
The phād water didnāt fix it, and I have to get a soil ph tester. Still have internal chlorosis of the new leaves. Will keep attempting to just give her lowered ph water and hope it fixes itself. Iām gonna possibly add epsilon salt to help with the sulfur, will add as a foliage spray.
Damaged leaves wont recover. So you are reading new growth or if leaves are getting better or worse. Itās tricky because of the lag in feedback will take several days to show up.
You donāt want to be chasing this either, that is over correcting. So itās much better if you can identify what is off going in vs waiting to see what happens.
The main reason itās hard for us, is there are many ways to get there as long a the needs are met. This is part of the initial learning curve most experience. When you see me harp on picking a system you like and stick with it. What you are going through is why I do that. I have an idea how you might be feeling because I remember when I was going through it myself at one point, I still run into issue sometimes when I make changes.
It takes time and these headache now will make you a better grower down the road. As of the last photo I saw your plant isnāt happy, currently a minor issue so address it accordingly. You concern me when you start by saying you think you added too much Epsomās salts and are now back to wanting to add more.
Also what is your water source, well, public tap, RO, bottled and generally where are you. See if we can reduce some of the unknowns while you gear up some.
How would u fix an iron or zinc deficiency, because from my research and everything Iāve gathered I agree thag I think itās iron.
I would refer back to my earlier post about this. You need to determin if there in lack of Zink/Iron OR if you are feeding at a pH that is out of range, or if the rootzone pH is out of range, the plant canāt uptake the nutrients.
Hi @Yvngstonie, I agree that the plant is exhibiting a deficiency in Iron and or Zinc. This is either because those elements are not present in the media, or that the pH of the root zone is too high or too low for the plant to uptake those nutrients.
If it was my plant, I would prepare about 3x the amount of water & nutrients you normally feed, and slowly water all of that in to flush out/clear out the root zone/media. Replacing the water & nutrients that are in there now.
If the issue is that micronutrients are not present in your nutrient regiment/water supply, you will need to buy a nutrient line that has all of the essential micro and macro nutrients that the plant requires.
So the ph of my root zone is round 7.8. I donāt know how to even get the root zone lowered. I tried using 6.2 ph water but itās not lowering it. I donāt know whatās sage for cannabis plants when it comes to lowering the oh of the soil. But Iāve washed it out and havenāt given it anything with iron. And i believe I over flushed. Been learning more and more. But it was over nuted so we flushed it and then the chrlorosis showed up, everything else is accounted for on the plant tho. Itās uptaking nitrogen, potassium, and phosphorus, has decently fat leaves so i magnesium might not be the issue. And the parent of the clones had grown in 8ph soil I believe, by accident because I didnāt know what I was doing. But there isnāt a lack of slufur or magnesium. And none of the fox farms nuted I have even have iron in it.
I think you could use compost tea for your next feeding, since the contribution of microbiology tends to acidify the soil.
What kind of compost tea?
I just wanna have a better understanding
You can find some online. I shared my compost tea recipe here: https://social.growithjane.com/t/share-your-organic-compost-tea-recipes/40408?u=rasta_free-man
Temps are actually a bit high in the 75-79Ā°F range