Options to add more potassium

[Stupidface]

Hi, so i've been growing with fox farm's line of nutes and the issue i'm running into now is a lack of potassium in flower. Last run i didnt catch it until i had some brown spots on the leaves and an increase in nutes took care of it. This run the points on the leaves are starting to curl up like they did last time so again i've increased feeding to stop it going further. I know that can also indicate light stress but it's not the case here. The bloom nutes are 2-8-4 so i feel like i'm giving more nitrogen and phosphorous than necessary just to get enough K in there.

I'm not looking to switch nute lines just yet as i still have a bunch left, so i looked into additives like AN's Big Bud which is 0-2-3. But that is still adding phosphorous i may not need and is $50 CAD per liter. Now i can get potassium sulfate dirt cheap so my question is, are there any downsides to mixing in powdered potassium sulfate with bottled nutes if i am careful about how much i am adding? I track the ppm going in and going out every watering to make sure i'm not over/under feeding.

Any advice or alternative solutions would be appreciated.

 

[Mayne]

you know, there is something at walmart called "no Salt", which is potassium chloride, which plants use. it also has silicon dioxide, again, good for plants. Maybe someone else can chime in on this idea.

I might try it just for testing purposes, because 2 weeks into flower, usually mine start looking like crap, and this might also be my reason,lol.