AnyponicsSystems · By budget
A hydroponic system under $100
Honest answer first: a complete hydroponic system with a pump, a grow light and proper testing gear does not fit in $100. The smallest one our design engine can produce costs about $561. What does fit is a passive "Kratky" system by a sunny window, and it's a genuinely good way to start.
Where the money goes in the smallest complete system
These are the parts every complete system needs, even the smallest one the engine will produce indoors:
| Part | Why it's there | Price |
|---|---|---|
| Reservoir tank | 4 gal — Light-proof, food-safe | $55 |
| Submersible pump (AC, 120V) | 80 GPH @ 7.4 ft head | $35 |
| LED grow panel (200W) | 14" hang height · ~200 µmol/m²/s · DLI 11.5 | $147 |
| Hydroponic nutrient (2-part) | A+B, 1 gal each | $59 |
| pH up / down kit | 1 qt each | $26 |
| pH + EC meter combo | Calibrate weekly | $37 |
| GFCI outlet + surge protector | Required for any water-near outlet | $40 |
Those seven lines alone are $399. Even outdoors with free sunlight, the smallest complete design is $520, because the reservoir, pump, nutrients and meter don't go away.
What $100 does buy: the Kratky method
Kratky is hydroponics with nothing that plugs in. Plants sit in net pots in the lid of an opaque container filled with nutrient solution. As they drink, the water level drops and an air gap opens around the upper roots, which take oxygen from it. You fill it once and harvest; there is no pump, timer or electricity.
- Container: an opaque food-safe tote or a few wide-mouth jars wrapped to block light.
- Net pots and media: 2-inch net pots and rockwool cubes; the engine prices net pots at about $0.49 each.
- Nutrient: a small bottle of hydroponic nutrient instead of the gallon jugs in a full build.
- pH test strips instead of a meter, and lemon juice or a pH-down bottle to adjust.
- Light: a bright south-facing window (north-facing in the southern hemisphere), or outdoors in the warm months.
Kratky suits lettuce and herbs, which finish before the water runs out. It doesn't suit tomatoes or cucumbers, which drink too much. Expect slower growth on a windowsill than under a grow light, especially in winter.
When to step up
If you're harvesting from a Kratky tote and want more, the step up is a pumped, lit system sized to your space. Most of its cost is the parts above, which barely grow with plant count, so a bigger first "real" system is better value than a small one; see systems under $500.