Backyard Aquaponics
A place to discuss aquaponics

Someone nearby is selling galvanized water troughs with holes. Could I use a thinner liner in that than the suggested 45mil normally used for in ground ponds? The 45mil cost just as much as a brand new stock tank.

I expect it depends on the use of the troughs. If you are panning on using it as a grow bed with gravel in it (where digging around can be hard on the liner), I would choose the heavier types of liner. If it is for a fish tank, perhaps a lighter weight liner might be ok if treated gently but remember a leak in the bottom of the fish tank could lead to HSM very quickly.