This information is from Nadja’s Garden - Permaculture Garden Design - Adelaide
( http://nadjasgarden.com.au/ ), and is associated with a post on FB using flexible tubs for wicking beds. I asked for a ‘fact sheet’ and some feedback on her experience with tub quality.
I’m glad you raised the question. I used the Ezy Storage flexi tubs (60L) from Bunnings ($6.50 each), not cheaper imitations. Yes, I have had other tubs (usually from hard rubbish collection) - some are brittle and cracked, others still going fine after years in the sun. These that I bought are BPA free and UV stabilised. I suspect that some colours and materials are much more durable than others. In general, if they are very flexible and ‘rubbery’ to begin with, they tend to maintain their flexibility better than those that feel stiffer. But being in partial shade is probably extending their life - which suits the kinds of plants that I like to grow in wicking containers (leafy greens, mint, coriander). *
****I hate throwing plastic into landfill so if my tubs do crack later I’ll be repairing and reusing them for storage (kindling for wood fire, materials in garden shed etc)."
PS. If anyone is interested, here is a link for the fact sheet: