Ignoring the question of whether aquaponics is a sustainable process (which it may not be due to seemingly high energy input required for water movement and filtration).
Most aquaponics designs use plastic as a basic building block for every component. Given plastics are not sustainable materials, I'd like to avoid their use in "backyard" DIY projects.
What are some safe, renewable, water-resistant materials I could use instead of plastic in existing designs?
Are there "backyard" designs that avoid plastic materials and components?