The principle
Cycle before you stock. Food-grade IBC only, a backup air pump as life-support, a water test kit that is non-negotiable, and no fish in the system until it is biologically cycled and legal with DGAV/ICNF.
Materials
- Old cast-iron/steel bathtub
- wood blocks/timber stands
- landscape fabric
- soil/compost
- drainage holes (if needed)
- anti-rust primer
Tools
- Drill (metal bit)
- wire brush
- paint brush
- shovel
Reclaimed from
Salvage yard tubs (€0–30) + timber props + offcut drainage pipes