Yeah I’m pretty clear on the roles of the NPK there’s a part A which is straight N and then the part B is just P&K instructions say to give it even amount of both but have started to give more part B than A
Your over feeding. I've used my fair share of pH perfect sensi grow, sensi coco and connoisseur in the past. pH perfect "technology", is nothing more thsn chelation. Im sure its not a Advanced Nutrients exclusive. If your coco based your schedule should be feed water feed.
Peat based is feed water water feed.
Always have 1/3ish runoff. Don't allow standing runoff.
Part A is your Magnesium Nitrate, Calcium Nitrate, and chelation to assist in a broader nutrient absorption range, pH.
I don't recall your water source or quality, but I'm quite certain your Calcium levels are too high, and very clearly your Nitrogen, hence the dark leaves. Too much Calcium inhibits the uptake of Potassium, even though Potassium is present and abundant.
This is why your sugar leaves are yellowing. It's not showing as much in the older fan leaves because of your high levels of N, Calcium and Magnesium and increased uptake of iron. Also another drawback of excessive chelation.
Someone suggested to do a flush with a mild nutrient charge. Good advise right there. You don't want to lower the nutrient too much with in the coco that you now have amplified deficiencies. Plus salt attracts salts, so a mild nutrient charged flush will actually correct the problem quickly by attracting more accumulated salts as it passes through the substrate. Getting you to your target EC more efficiently.
Lastly with any bottled nutrient I've learned to cut the dosing recommendations in half.
If the plant can take more then change your feed schedule to feeding daily rather than feed water feed. Environment and light are a huge factor in determining the capability of your plant to assimilate nutrient, consequently grow.
