Hi am going to put pics up of my defiensey it in m...

hey there FG, that's not PK , that 's VERY SERIOUS calcium deficiency, the difference is that calcium deficiency is more spots than "blotches" and for PK deficiency you usually see colorful areas, here you only see brown spots that are growing. What happened is during the flower stretch the plant uses a lot of calcium and magnesium and you have a very big light schedule 20Hs, so the plant is in over drive and basically there is not enough calcium in soil for and the plant roots are not good enough to take the calcium quick enough... So you need to add calcium - magnesium to the feed, and if you want you can do a 3ml/L cal mag spray, the spray works quicker. For sure dont flush because that will stress the plant more and fore sure dont add crazy nutrients because then you will have a burn.

Thats PK for sure , your run off should be like that either . You should always let your water sit for a minimum of 24 hours before using it to feed with your plants , but that wouldnt cause the damages Im seeing . I would fix up your nutrient solution to be stronger on the bloom side of things and trim away all those damaged leaves in order to prevent any unwanted pests from making themselves a nice home . This isnt a problem thats going to fix itself right away its going to take some time but it is 100% fixable . As for the PH issue its really hard to say the "why" on that because I dont know what your soil's mix is . An example I could give you tho is that say your soil already has fertiliser in it already not because you added some but because it comes with it and then you add some nutrients to your water and feed you will eventually get a lower PH because the ferts are going to pile on top of one and other leading up to what we call nutrient burns . The best advice I can give you is to flush your soil with PH corrected water so in your case 6.6 and try to reset the balance . Your run off will always be a little bit different then what your feeding but when its drastic like that there a problem . So if your soil already has fertilisers in it then that would be the "why" to your drastic PH changes in the run off . I hope this information helps you understand a bit more about your problem with the solutions to fix it :) -Happy Growing!