First, you've got some nute burn (the yellow tips) and second, you're starting to get a calcium deficiency (the brown spots)... but we need a diary to tell you WHY these things are happening to your plant... and then what you can to for it.... for example, the calcium deficiency could be the result of nitrogen toxicity (which would also account for the nute burn but...), it could also be because you're pH is out of range... has nothing to do with lack of K... and if you can't figure out WHY you are getting a calcium deficiency, you could throw as much calmag at the problem as you want and it wouldn't help...
Please start a diary with as much information as possible - it's not necessary to go back to Day 1... just put up last week and this week... that would be enough for us to figure things out... Start the diary and then come back with your question again - this page is NOT like a chat so even if you tag someone in a comment, no one is notified you've done so...
Good luck