Medium for Strawberry Towers

[john dawyot]

I am making a set of Strawberry towers for my school's aquaponics system and I was wondering if using a well graded medium was preferable to a uniform medium as far as particle size went (assuming that none of the particle sizes of the medium would be small enough to fit through the drainage slit). .

[Wendell Ford]

I used hydroton in my towers and are doing good, water flows through great. I am going to try larger drainage rocks in my next set.

[john dawyot]

Hydroton was recalled so I'm not going to use that. I was thinking about limestone gravel maybe? This would keep the pH from dropping to low.