PVC NFT Channel System (Recirculating Greens Wall)
Nutrient Film Technique: a thin stream of nutrient water runs down sloped PVC channels, past bare roots, and back to a reservoir. High yield in a small footprint, and it uses very little water.
Estimated cost
$180 – $280
Estimated time
4 – 6 hours
Lifespan
8+ years for the frame and channels
Soil needed
None — net pots with clay pebbles
Weight empty
35–45 lbs
Weight full
250+ lbs with a full reservoir
Best for
Lettuce, herbs, strawberries, kale — 36+ plants in a 6 ft × 3 ft area
Placement
Level ground is critical. Set the frame with a slight 1:30 slope (about 2 inches of drop across a 6 ft run) so the film of water keeps moving.
Boards to Buy
| Boards to Buy | Quantity | What You Use Them For |
|---|---|---|
| 4-inch PVC pipe, 10 ft lengths | 2 | Cut into three 6 ft grow channels |
| 4-inch PVC end caps | 6 | Cap both ends of each channel |
| 1/2-inch PVC pipe, 10 ft | 4 | A-frame legs and cross braces |
| 1/2-inch PVC elbows and tees | 16 | Frame joints |
| 27-gallon tote or 20-gal reservoir | 1 | Nutrient reservoir under the frame |
| Submersible pump, 400+ GPH | 1 | Feeds the top of each channel |
| 1/2-inch vinyl tubing + barbed tee fittings | 20 ft | Pump manifold to channel inlets |
| 3-inch net pots | 36 | Two-inch spacing rows down each channel |
- ·PVC cement and primer
- ·Silicone sealant (food-safe) for the end caps
- ·Clay pebbles and 1.5-inch rockwool cubes
- ·Hydroponic nutrient set, pH pen, pH Up/Down, TDS meter
- ·Outdoor-rated timer or a GFCI outlet
Steps
- 1Cut the 4-inch PVC into three 6 ft channels. Deburr the cut ends.
- 2Mark net-pot holes down the top center of each channel, one every 8 inches. Drill with the 3-inch hole saw and sand the edges smooth.
- 3Glue an end cap on each end of each channel. Drill a 1/2-inch inlet hole in the top of the high-end cap and a 1-inch drain hole in the bottom of the low-end cap.
- 4Build the A-frame from 1/2-inch PVC: two triangular ends joined by cross braces, with the channel rails set at three heights so channels stack in tiers.
- 5Set the frame level side-to-side, then shim so each channel drops about 2 inches over its 6 ft length. Check with a level — too flat and water pools, too steep and roots dry out.
- 6Place the reservoir under the low end so all three drains empty into it.
- 7Mount the pump in the reservoir. Run the main line up the frame and split it with tees to each channel inlet.
- 8Test with plain water first. Run it 20 minutes and check for leaks, pooling, and even flow in all three channels before you add a single plant.
- 9Mix nutrients in the reservoir, adjust pH to 5.5 – 6.2, and check EC (about 1.2–1.6 for leafy greens).
- 10Transplant rooted rockwool cubes into net pots with a few clay pebbles for support, then drop them in the holes.
- 11Run the pump continuously during the day. Many growers run 24/7 on NFT; a 15-min-on / 15-min-off timer also works once roots are established.
- 12Cover the reservoir and any exposed tubing to block light.
- 13Top off daily with plain pH-adjusted water; change the full reservoir every 2 weeks.
Tools needed
- ·3-inch hole saw + drill
- ·Miter saw or PVC cutter
- ·Tape measure and level
- ·Deburring tool or sandpaper
- ·Safety glasses and dust mask
Common mistakes to avoid
- ·Channels not sloped, so water pools and roots suffocate
- ·Undersized pump — flow should be roughly 1 quart per minute per channel
- ·No backup plan for a power outage; NFT roots dry out within a few hours
- ·Net-pot holes cut too large, letting the pot fall through
- ·Skipping the plain-water leak test before planting
Maintenance tips
Flush the channels between crops with a mild hydrogen peroxide or vinegar solution. Clean the pump inlet screen monthly. Watch for root mats blocking flow at the drain end and thin them out.
Community builds
See how other gardeners built their pvc nft channel system (recirculating greens wall) — and share up to 3 photos of yours.
Sign in to view photos other gardeners have shared.
Sign in to share photos of your build.