I fuckin love Jacks. I use both Classic and Citrus. Usually switchin mid flower to provide a little extra N for stretch in the beginning.
No issues, no deficiencies (mayyybe a little mag problem towards the end of my Blueberry Hill, but she was wanting ton of N throughout flower so heavy ferting for her compared to different strains), it works wonderfully and so cheap. I regret not buying the larger tub of Citrus instead of the smaller one).
I'll post my curing nugs from all Jacks grow (only added fulvic acid maybe twice, silica (2x) and a few molasses waterings) in a bit