Hey Roasty,
I have a bunch of Biotabs, how about I send you some to try in conjunction with your current Organic mix? I was think that maybe you do your normal mix and around day 30ish you drop a few tabs in to help with the second half of your cycle? Get the tabs in a week or Two before they get hungry? We know it's too late by the time they show symptoms. I have a bunch of gbd Super Soil too, but I rock Coco so organics have not worked out like salts. I will say the smells and taste from even the small Coco Organic plants is stellar. The buds usually turn out nice, but the leaves not so much.
I usually rock small pots and aim for quick turn arounds. However life has thrown me some curve balls lately and I have been using bigger pots because I am super busy. I'm not a fan of massive plants, and when I use 2gal or more my plants in Coco with salts get massive. When I tried Super Soil last time with Coco in 2 gal pots they ran out of steam halfway through. I am going to give Super Soil one more shot in Coco, in a 3 gal pot with Sour Crack Seeds. Sour Crack Is the fastest strain I have. So the Organic mix doesn't need to last as long as a 10-11 week Strain. My plant is to use Super Soil as Directed in 3 Gal pot and use 2-3 pices of PVC pipe to keep a few holes open to insert a Couple Biotabs around day 30. Insert tabs, remove PVC, cover the hole up and water as usual. I am hoping this will work? I also have Recharge, but I am hoping this Combo will work. The plants always looked perfect, til a little past halfway point with SS. Biotabs and Coco plants had similar results and get hungry around the same time. I will take a reduction in yield for nice Organic buds, if we can get the yields up and get them to finish nicer looking. I am used to certain standards.
BTW, I am curious...are you using RO water only for them and are you pHing your water?