In designing an aquaponics system for your garden there are a few basic guidelines that seem to work. They cover things like the amount of fish you can stock, and the relative size of your tank and growbeds. Here are some of the main points:

  • Ideal depth of the gravel in a gravel-filled growbed is 300mm – this allows for the best conditions for plant and bacteria growth.
  • Use a 5-10mm particle size gravel for the best surface area for bacterial growth – smoother gravel makes for easier planting.
  • Maximum advisable stocking level is 6kg of fish per 100 litres.
  • Growbed volume should be twice the volume of the fish tank.

That should be enough to get me started on my basic design!