DIY Hydroponic PVC Pipe System

Materials

1. One small mesh per plant (i.e. 31/2-inch).
2. Two sawhorses or 4 cement blocks.
3. One alligator stake per plant.
4. One 1/8-inch fitting per plant.
5. One 8 to 12-inch piece of 1/8-inch tubing per plant.
6. One reservoir.
7. Two 4-inch elbow fittings.
8. Two 4-inch pipes cut to equal lengths that are used to hold the plants.
9. One T-fitting for each length of 4-inch pipe.
10. Mag drive pump.
11. Bypass valve.
12. 1/2-inch black poly tubing for header lines.
13. Two 1/2-inch black poly elbows.
14. 1/2-inch black poly Ts for each pipe.
15. 1/2-inch black poly end cap for each header line.

Tools

1. Drill.
2. 31/2-inch holesaw.
3. Knife.
4. Wrench.
5. Handsaw or skillsaw.

Procedure

A. The 4 to 6-inch pipe will be placed on something that supports it, like two 2x4s and four cement blocks. (Figure 4.80) A quick sawhorse can be made with cheap 2 to 3-foot lengths of 2×4 wood with hinges that the 2×4 wood slides into. Another 2×4 is placed between the hinges to complete an instant sawhorse. (Figure 4.81)

B. Two (or more) sawhorses can be used to support the connected pipes. Two sawhorses support an 8 to 12-foot length of 2×4. When the sawhorses are made, the side furthest from the reservoir should be the highest and at equal height. The side nearest the reservoir should be 1 to 3 inches lower for every 8-foot length so that the solution drains back into the reservoir.

C. All piping (i.e. 4-inch PVC) should be cut to the desired length.

D. All lengths of large pipe must have end caps attached to the higher ends that are located at the far side from the reservoir. (Figure 4.82)

E. All large 4-inch pipes except the first and last pipe are connected to their neighboring pipe with T-fittings. The first and last pipe are connected with 4-inch elbows. For example, 4-inch pipe will use 4-inch T-fittings. Small pieces of 4-inch pipe are placed between the T-fittings in order to connect the T-fittings and give the desired spacing (i.e. 10-inch centers). Piping and fittings can be glued with PVC cement (for PVC pipe), but the connections will be permanent. The system will not leak without glue if quality PVC is used. A little bit of duct tape can be used for securing connections so that disassembly is easy. (Figure 4.83)
Note: One of the 4-inch PVC elbows will have a 3/4-inch thru-hull inserted into the bottom for draining. (Figures 4.83 and 4.84)

F. 31/2-inch holes should be cut in the pipe at the desired spacing (8 to 12-inch centers). The hole sizes must match the pot sizes to make a custom fit. (Figure 4.86)

G. Header Line Setup
1/2-inch poly tubing should be run along the outside of the pipes until it reaches the end. It should be cut to a length that reaches the middle of the T-fittings and elbow fitting that will be connected to the larger pipe at the shorter end. The 1/2-inch poly tubing must have a 1/2-inch end cap at the end.

Another 1/2-inch poly line will run over the 4-inch T-fittings and the 4-inch elbows. This tubing will be connected to the other 1/2-inch lengths with 1/2-inch PVC elbows at each end and 1/2-inch PVC Ts for each other length of 1/2-inch tubing. (Figure 4.87)

H. Small holes should be punched into the 1/2-inch header line for the feeder tubing (i.e. 1/8, 3/16, 1/4-inch tubing) to be connected.

I. Fittings (i.e. 1/8, 3/16, 1/4-inch) should be inserted into each hole with barbed fittings or fittings with thread on one side and barb on the other. The threaded fittings are the better leak-free method, but are more time consuming to assemble. If barbed fittings are used, small drop leaks can be sealed with silicon applied to dry pipe.

J. The feeder lines are connected to the fittings. The appropriate sized tubing should be connected to the fittings in the header line on one side, and connected to a stake in the pot. In addition, 3/16-inch tubing should be connected to a 3/16-inch fitting, while 1/4-inch fittings would use 1/4-inch lines. The tubing should be cut to a length that will reach the larger hole (for the pots) or stake with slack. (Figure 4.88)

K. The outside of the thru-hull fitting in the 4-inch elbow can be connected to 3/4-inch hose that leads back to the reservoir.

L. A 1/2-inch line runs from the pump to a 1/2-inch PVC T that is inserted between the middle pipes. (Figure 4.91)

Recommended Option: A 1/2-inch poly T should be inserted a few inches above the pump that sits at the bottom of the reservoir. A small 3-inch piece of 1/2-inch poly tubing is connected to the 1/2-inch T. A bypass valve should be connected to the small piece of 1/2-inch tubing to control the flow rate.

In addition to a bypass valve, drippers can be inserted into the ends of the the small feeder lines. This creates even feeding for each pot and allows more pressure in the system so we can use our pump with efficiency. The most common size to find drippers is 1/4-inch. The come with flow rates like 1/2-gallon(2 litres)  per hour and 1 gallon per hour.

Feeding

It is easiest to feed the plants with the pump timer running full-time during the light hours, but plants can be fed continuously all day and all night. Or plants can be fed intermittently for 2 minutes every 20 minutes during the light hours, or for 24 hours a day.

Aeroponic Conversion

A. Each feeder line (3/16-inch) that is connected to a pot is removed.

B. The 1/2-inch lines that run down the outsides of the 4-inch PVC pipes are disconnected from the 1/2-inch PVC Ts and elbows. (Figure 4.92)

C. Steps G to J are repeated. The slight differences are listed below.
1. A threaded fitting is used to connect the feeder tubing to the 1/2-inch lines.
2. The small feeder line runs through the pot. (Figure 4.94)
3. A 11 to 13-PSI mister is inserted into the end of the feeder line. (Figure 4.94)
4. The pump should be changed to a high-pressure pump designed for aeroponics. The pump should be the size required for the garden dimensions. A 1,200-gallon per hour pump will work with 11 to 13 PSI misters.