i think i may have answered this in one of the posts u had responded to but it was biobizz coco mix and biobizz light mix that i used for all my out door stuff.... i add vermiculite, perlite, ew castings, blood meal, and sometimes sphagnum moss on top as mulch. Both the coco and light mixes hold water really well and i feed often... usually every 2-3 days so if they held too much water i'd notice by now with adverse affects on plants but haven't seen anything. I feed often and heavy with the biobizz nutes and foxfarm soluble beastie bloomz and no burns at all! Hope this helps