Water in hydroponic systems needs to be discharged periodically, as the salts and chemicals build up in the water which becomes toxic to the plants. This is both inconvenient and problematic as the disposal location of this waste water needs to be carefully considered.
In aquaponics you never replace water; you only top it off as it evaporates.
1/10 water use
Instead of using synthetic chemical solutions to grow plants, aquaponics uses highly nutritious fish effluent as an organic feed stock, that contains all the required nutrients for optimum plant growth.
Instead of discharging water, aquaponics uses the plants and the media in which they grow to clean and purify the water, after which it is returned to the fish tank.
This water can be reused indefinitely and only needs to be replenished when it is lost through transpiration and evaporation.
Hydroponics is all about growing in a sterile, man-made environment. Traditional hydroponic systems rely on the careful application of expensive nutrients made from mixing together a concoction of chemicals, salts and trace elements.
In aquaponics you are creating a natural ecosystem where you rely on beneficial bacteria that breaks down and converts the liquid and solid waste from the fish into a complete plant food. If pesticides are applied to the plants, the fish will suffer. If growth hormones or antibiotics are given to the fish, the plants will suffer.
This natural ecosystem results in a completely organic lifecycle.