would it work to do a chunky coir or chow mix watered several times a day as long as you had enough plants to meet filtration requirements? i think there would be a balance between daily waterings, runoff, and plant count that would have to be ironed out, but it seems viable. i use a water soluble fertilizer with 25% ammonia in a coir mix and get great results. the only reason i can think of why you want to do a continual flood/drain with a bell siphon vs coir medium- the amount of filtration you get within a 24 hr period. i've only played around with a lettuce raft, so i'm admittedly newb when it comes to AP, but the method might need slight adjustment for cannabis to thrive.
have any of you experimented with rock phosphates or granite for an AP medium additive with cannabis or flowering vegetables? granite is an iron and potassium source, rock phosphate is mono-, di-, or tri-calcium phosphate, each have different solubility over time. mono is most soluble in a short time frame to tri which is least soluble.
i'm just curious how the fish would respond to both of these scenarios, or which fish would tolerate such conditions.