2 bathtubs

[Brian Hillestad]

I just became in possession of 2 old bathtubs.  They are in good condition.  One is cast iron, the other is fiberglass.  I was going to put fish in one and grow bed in the other.  Would there be a preference as to which one I would use for the grow bed?  Any advice would be appreciated.

[Harold Sukhbir]

Hi Brian,

Metal for use in Aquaponics is not recommended as it leaches into water and is absorbed by plant, fish and ultimately humans. Fish are highly sensitive to some metals buildup and eventually die. In a marine environment leaching can lead to bio-magnification. 

[TCLynx]

Yes as Harold notes, you want to make sure any metals are well protected from the fish water.  make sure there are no chips in the Iron tub's enamel.  If it is a deep Iron tub, I would probably say use the deep tub for the fish.