What about adding some greensand, azomite, humate, humic/fulvic acid rock phosphate (if you can find it), Mycrohorzae's, EWC and then if you wanna add some more nutes to the mix throw some bloodmeal, bone meal some of that guano you got, kelp meal etc. YOUR PLANTS WILL LOVE YOU!
I re-use my soils but I only grow in pots but have been really thinking of bringing a raised bed indoor. When my plants finish in their pots I just put all the used soil in a trash can add amendments and let it sit for a couple months come back and it'll be all white and fuzzy throw my plants in and only water until chop