What causes the leaves to turn this color? Maybe m...

many possibilities with interveinal chlorosis -- check any leaf symptom chart with a simple google search to see. Mg deficiency would come with rust spots. So, probably not that. Also, for future reference, Mg deficiencies actually start 30+ days before you see a symptom. so, it is important to keep track of how you feed a plant to more easily diagnose such things. e.g. i just started playing with Mg concentration in my formual. i've stepped down twice and took not on my calendar about 30days out to pay attention for symptoms showing... that's how long it takes... a lot of trace elements can cause this symptom, but this would be rare. Ensure pH is proper. If you see some rust spots show up, i'd go with Mg-def. So, best to give this a second to more easily discern what the cause is. download a leaf symptom chart even if you continue to ask questions.. try to diagnose everythign you encounter and evenetually you get familiar with it.

This is potassium deficiency, nitrogen start from the bottom and go up...

I'm also thinking Mg. epsolm slats should work fine, some extra S in that but should not cause to big of an issue. Good Luck!

Magnesium and nitrogen. Overall, increase the dosage of fertilizers. I had the same problem under LED lighting, I had to increase by 50%, sometimes even 100%. Try to look into my questions, one of the locals commented on it✌️

Yes. I found big corelation between overwatering in soil and lack of magnesium. 200 ppm of epsom salt or branded calmag 0.5 ml/L should sort it out. i use all additives on plain watering days, dont mix with main food, found it works better in soil.