Yellowing leaves with dark spots?

Hi everyone, checked runoff and is 6.2, double checked everything for days, and it seems a nitrogen deficiency to me. @Bill_the_goat72 the runoff is ok so the problem is not there. @Shemshemet it's not a "scam" the % of Cal is 4.2% and Mag is 1.7%, pretty standard. @GrowCN thank you for the useful link, got to the problem by checking every deficiency or toxicity! @ChitownCannaChica overwatering? wth.

Your locked out check your run off make sure your pH is correct for stage of growth.

That BioBizz CalMag looks like a bit of a scam; try a Ca/Mg product that lists the percentages on the label. If the rest of the BioBizz labels are to be believed, you'd get best results using... - 3ml/L Bio-Grow - 1ml/L Bio-Bloom - 0ml/L Top Max - 0ml/L CalMag + Some other reputable Ca/Mg source You might also be low in trace elements and sulphur, as they're also not listed on the Bio-Grow or Bio-Bloom products.

Growing granny giving bad advice again! It’s from over watering or watering too frequent between dry back periods.

This is looking like a typical calcium and magnesium deficiency ... and looking through your diary, I would say the culprit here is too much nitrogen which has caused a lockout of those two nutrients. And when you have a lockout, you can throw an entire bottle of calmag at the plant and it won't solve the problem because the plant just can't get at it. You've got two choices - do a hard flush with 3x the pot volume of pH'd water through it giving the plant a 1/2 strength dose of nutes at the end - or give her nothing but pH'd water for a week and then resuming the nutes but cutting down on the BioGrow as that's where most of the nitrogen is coming from... In either case, you should probably reduce the BioGrow going forward and increase the calmag dose (but only give it once a week). Good luck! (And there's nothing wrong with trimming off those damaged leaves - for one, the plant will LOOK nicer and for two, they're not doing the plant any good any way... if you don't see a continuation of the problem, you'll know you have solved it).