K issues?

In in promix and peat moss mix.
Feeding own to earth 4-4-4 and seabird guano 0-11-0 and also TPS Signal terpene booster. Looks like K and maybe mag issues. How can i fix?

I would say it’s a progressive calcium deficiency, give it a look up seems more of the style of calcium lack.

I looked at Signal by TPS. States on it that it is a phosphate hydroxide and 2 proprietary acids. Ph issue perhaps those look like hydroponics nutrients.
I would suggest running some 6.5 water through it.