The question has been asked regarding a suitable plastic sheeting liner that will be appropriate for hydroponics and aquaponics.
The key is using materials containing only virgin resins. In the past, quite a lot of 12 mil, 20 mil and 30 mil black polyethylene made from 100% virgin resins has been used. In more recent times, it seems a lot of people like white materials. The DuraSkrim R20WW, 20 mil White, reinforced has been the most popular product. There are other liners that can meet these requirements as well. The Rufco, film is also used regularly in this application. These films are guaranteed fish and plant safe, are strong and durable.