Hey there fookdogg. I use Biobizz ferts and looking at the info you've given, you seem to be following the feeding reigime fine. I would suggest you give your plants a flush through. There is a guide to flushing at the top of this forum. I would guess that you have a salt buildup in your soil that is locking out some of the nutrients. I flush my plants every few weeks to every month so I know exactly where I am with my fert programme. It gives you a clean slate to work from. Hope this helps and I'm sure you'll get some more suggestions soon.