AnyponicsSystems · Aquaponics
An aquaponic system for beginners
Start with a media bed: a bed of clay pebbles above a fish tank, flooded and drained by a bell siphon. The pebbles hold the plants and act as the biofilter at the same time, which removes the part that most often goes wrong. The designer picks it for every beginner who asks for fish.
Three beginner builds
| Setup | System | Plants | Build cost | Running /mo | Harvest /mo | Payback |
|---|---|---|---|---|---|---|
| Indoor, 10 goldfish, herbs (8×10) | Aquaponic Media Bed | 24 | $988 | $29 | 2.9 lb | 5+ years |
| Indoor, 12 tilapia, greens & herbs (10×12) | Aquaponic Media Bed | 40 | $1,222 | $32 | 35 heads (11.5 lb) | 5+ years |
| Greenhouse, 20 tilapia, greens (10×12) | Aquaponic Media Bed | 40 | $1,329 | $17 | 35 heads (11.5 lb) | 5+ years |
For comparison, a hydroponic greens system in the same 10×12 ft room costs $703: aquaponics adds a fish tank, test kit and the bigger media bed. In return you replace bottled nutrient with fish feed, and you get the fish.
How many fish for how many plants
The engine sizes the tank at about 0.5 lb of fish per gallon at adult weight, and estimates plant capacity from daily feed. Feed is the real input: fish eat roughly 1.5% of their body weight a day, and bacteria turn their waste into nitrate the plants use. For a media bed that supports roughly 25 plants per kilogram of daily feed. Too many plants for the fish and leaves yellow; too many fish for the filter and ammonia rises. Our fish-to-plant ratio guide has the details.
The part that takes patience: cycling
Before fish go in, the system needs a colony of nitrifying bacteria. Add an ammonia source with no fish, test daily, and watch ammonia rise and fall, then nitrite rise and fall, then nitrate climb. That takes 4–6 weeks. Stocking fish into an uncycled system is the classic beginner loss.
Which fish
- Goldfish: hardy, cheap, not eaten. The best fish to learn on.
- Tilapia: fast-growing and edible, but need warm water (72–86°F) and are regulated in some states.
- Catfish and perch: edible, tolerate cooler water than tilapia.
- Trout: need cold water, which means a chiller indoors in summer.