Aquaponics systems combine aquaculture (raising fish) with hydroponics (growing plants without soil). In aquaponics, grow beds are where plants grow and filter the water that cycles from the fish tanks. There are several types of aquaponics grow beds, each with its pros and cons:
Description: Beds are filled with inert media like expanded clay pebbles, lava rock, or gravel. Water from the fish tank floods and drains (flood-and-drain or ebb-and-flow cycle).
How it works: Media provides root support, mechanical filtration, and biofiltration.
Description: A thin film of nutrient-rich water flows through narrow channels or pipes, where plant roots dangle and absorb nutrients.
How it works: Water is continuously circulated in a thin layer, often using PVC channels.
Description: Plants grow on floating rafts (typically foam) with their roots suspended in water.
How it works: Water from the fish tank continuously flows through the raft bed, providing nutrients and oxygen.
Description: Plants are stacked vertically, and water is trickled or pumped from the top and collected at the bottom.
How it works: Gravity moves water down through channels or grow cups, feeding each plant.
Description: A reservoir of water below a soil bed allows moisture to wick upward to plant roots.
How it works: Wicking action draws nutrient water upward; useful for root crops.
| Type | Best For | Pros | Cons |
|---|---|---|---|
| Media Bed | Mixed crops | Simple, great filtration | Can clog, heavy |
| NFT | Leafy greens, herbs | Lightweight, efficient | Not for large plants, prone to clogging |
| DWC / Raft | Leafy greens | Stable, scalable | Needs aeration, space-consuming |
| Vertical Towers | Herbs, strawberries | Saves space | Can dry out quickly, complex |
| Wicking Beds | Root crops | Hybrid approach | Not widely used in aquaponics |