I'm designing a wicking bed now for my garden in Taiwan. The climate is very similar to Houston, TX.

I'm going to use plastic milk crates as a void for water in my reservoir. They will be wrapped in weed cloth. All around and above those wrapped crates will be sand to act as the wicking substance and above that my growing substrate.

I'm finding old milk crates from all over and it's dawned on me that I don't know what's been in them. Obviously I'm going to scrub them. I thought I would do a soap and bleach mix, rinse them, and follow that with a soap and baking soda scrub.

Realistically, is this enough of a clean to feel safe using them as a reservoir? Of course, I'm using milk crates that are reasonably clean. Any thoughts on this?

Thanks

Zin