Osmocote 19-5-8 Slow Release Fertilizer w/minors. Looks like pretty good stuff, and has calcium and magnesium. My daily fertigation on a number of fairly large containers is a bit labor intensive during the heat of summer, in addition to all the watering by hand. There's a $10 coupon for first time buyers. The bag should last me several years, but I'll probably be tempted to use it on my in-ground plants too, so it'll probably be gone in a year
https://www.amleo.com/osmocote-19-5-...ilizer/p/1958/