the tower would work fine as far as structure goes; i saw a video from a midwestern university where they were installing a pvc tower as a way of blocking sunlight in the greenhouse from reaching the fish reservoir, raising nile tilapia (block light, and create tower for growing is win-win)
structure wise it works good for hydro systems probably. as far as aquaponics i am not 100% but i think it works fine for vegging and what not but when you hit flower unless you have the tank cycled proper and a large amount of fish the nutrients just arent good for flowering/fruiting plants. i know people who have done tomatos and what not in aquaponics systems but the successful non-commercial systems typically use koi/goldfish, cleaners like bladder/ramshorn snails, and plants like basil, bok choy and lettuce
also i feel like pithium and root rot is higher chance in an aquaponics system versus a hydro. anyway cool stuff and good luck to ya