Yellowing of the leaves in week 6 of flower

Calcium deficiency is present. Need more Ca in your fertilization. i don't think the interveinal chlorosis is Mg related... peat moss is a soilless medium. if you compare ppms to the following, it will help diagnose the symtpoms N 120-130 P 60 K 180-200 Ca 100+ Mg 50-75 S 100+ Autoflowers can handle 1.3-1.5EC (fertilizer only, ignoring solutes in the water before you mix). There's no reason to baby them. Feed them a well-balanced diet at all times in sphagnum peat moss. fertilze everytime with 10% runoff at above concentrations - or near.. ballpark values, but ratios are solid. overall concentratio may need slight adjustment due to local variables. soemthing to ponder -- if you changed formula recently and upped p or k, this could cause chlorosis in new growth. There are so many things that cause chlorosis.. unfortunately. fertilization is about the compounding effect over time... what you see today may have been caused by your behaviour over the last severa weeks and even greater than a month... if rate of provision is off slightly from rate of use, it takes a long time to see the issue. Take notes.. keep track.. makes diagnosing easier. once you have a great formule working on 99% of plants (always oddball genetics possible), you don't have to track this stuff anymore.