Pk13/14 ?

I don't subscribe to boosters as they are marketed. Can be good for rounding out a mix, of course. usually something like monopotassium phosphate regardless of label. plants prefer a happy range of concentrations of the various elements in which lockout does not occur. (and relative to an optimal pH and ambient environment in general.) too much P or K and you'll lockout Ca, Mg, Fe, S, et al... lol. it'll be a mess. So, there's no magic bullet here. There;s no magic product that'll impact your plants more than good lighting or increased CO2. the rest is not screwing up, staying out of the way... 5-10% of the total pie. Know your PPMs of what you feed based on guarnateed analysis info before adding anything, unless you are mirroring a successful grow or something akin to that. Even so, read and adjust to plant. You see all sorts of issues crop up after using, assume it's an overdose and back off, try again with lower dosage. don't blindly use products. there are nute calculators online. i have a spreadsheet linked in my GD profile comments. should work for liquid nutrients, but no guarnantees. my nutes are dry and mixed when used. Specific gravity becomes a concern with some labeling values. should be notated in the instructions.