1st grow all auto

not bad! good luck

The yellowing *between* veins is magnesium deficiency. Cal mag with the water should help without hurting. https://www.growweedeasy.com/why-cannabis-leaves-yellow/#magnesium-deficiency by the way there are really good resources on that site for further diagnosis needs.

Any soil is just good enough for 3-4 weeks , after this all nutrients have been used/or/washed/or/have turned into NaCl. Thinking in week 5 to tweak and mix your nootz wasn’t the smartest thing to do, particularly when you have no experience and no EC/TDS meter 😊😉 Using only 0.15 ml/l of a 4-3-3 when they started to stretch sounds poor when you’re supposed to be not far away from max feeding. When cannabis plants stretch, they use a lot of Nitrogen, this is where you must make sure they have plenty enough, when the stretch is over the roots will only concentrate on P and K for the flowers and won’t absorb Nitrogen anymore. The plant is sacrificing the bottom to save the top and is moving its Nitrogen stocked in the leaves... So no need to worry as you can see she’s got plenty of stock, she’s gonna loose her leaves very slowly, one by one, a day after another, they will be no sudden death. Don’t try to fix the Nitrogen deficiency by nuking your plants with massive amounts of nutrients thinking it would help... it won’t. Just let it do her thing and keep on doing like your doing now, it will finish itself smoothly and you will probably won’t need to flush it.

Nitrogen deficiency is what it looks like to me. During flowering your plant will be using every bit of energy stores in their leaves, this can result in the yellowing you're seeing. However, if this worries you add a lil bit of (or lil bigger dose, if still applying) grow nutes this may help. Since were on the topic of nitrogen issues: If your leaves look nice and healthy, but the tips are curling downwards...that would be nitrogen toxicity and it's time to back off on the nitrogen some.

Buds are looking nice this week! It looks like your yellowing isn't going away. You might never get a handle on it this grow. You are about halfway through flower, and these problems aren't solved overnight. Not only that, but you will start to get a lot of leaf fade as the flowering continues. Try to minimize the problem using the advice given by some of the excellent growers on this site. Based on my reading, they've covered all sorts of remedies that should help a lot. Then just relax, and remember this experience for the next grow. The plants look healthy overall. You just have a stubborn problem that needs a solution. 😎

Ugh I feel like yellowing leaves is like 75% of all our problems on here lol. https://www.growweedeasy.com/why-cannabis-leaves-yellow/ Maybe this will help I saw you're PH-ing so maybe one of these other problems applies? Best of luck happy growing