Building a DIY Hydroponics System Part 1: The Rails

Building a DIY Hydroponics System Part 1: The Rails

Before you dive in: If you are taking our 'Building a Home Hydroponic Farm' video course, this tutorial uses different fittings. The parts list for our video course is located here.

In case you haven't heard, we've created a full video course going through all the steps of building and setting up a 2 or 4 rail home hydroponic system. We show you every step as we build it and we think you'll find it very helpful! We've also slightly updated the design to reduce the cost of fittings.

If you'd like to try the video course for free, we've also posted the course to Skillshare where you can sign up for a free trial.

The first place you'll need to start is building the rails. This piece of the system is where your plants will dwell, and what you'll be looking at the most! Each item on the supplies list is linked to websites where you can buy everything you need online, but you can also find these items in local hardware stores or other websites if that suits you.

(For more details on how these rails are incorporated into the overall design, and the "whys" behind the design, visit the Overview page.)

Other Articles in this Series:
Part 2: The Support Structure
Part 3: The Reservoir
Part 4: Lighting
Part 5: Nutrients
Part 6: Planting
Part 7: Harvesting

Note about links: We have linked to certain products that we have found useful when building our hydroponic systems. Some of these links may be affiliate links and as an Amazon Associate we earn from qualifying purchases after clicking one of these. We take great care to only link to products we have found to be useful - products we would recommend to a friend or family member building this system - but you are more than welcome to use other products instead.



  • Cordless Drill or Reversible Drill Press
  • Hole Saw Arbor (Amazon - this requires drill with 1/2" chuck)
  • 1.75" Hole Saw (Amazon)
  • 1.5" Hole Saw (Amazon)
  • 1.25" Hole Saw (Amazon - this fits the same 1/2" arbor)
  • Sandpaper or Rotary Tool
  • Caulking Gun (Amazon)
  • Large Wrench or Tongue and Groove Pliers (10") (Amazon)
  • Measuring Tape (Amazon)
  • Ruler with Tenths of Inches (Amazon)
  • Marker
  • Safety Glasses

Step 1: Prepare

  • Before you get started, we suggest you plan ahead for what you're about to do.
  • Find your safety glasses for this project, as sawing and drilling the PVC fence post can throw around small chunks of plastic. It is also good to do this in a location that can be swept or vacuumed as there will undoubtedly be PVC shavings. A garage is usually a good option.

Step 2: Cut the Rails and Connection Piping

  • Cut the 4" Square Fence Post in half, creating two 50" sections. A miter saw works great but we have also used a circular saw or a hand saw. The cuts should be as flat as possible to allow for the end caps to fit on nicely in a future step.
  • Cut two 2-1/8" lengths of 1" Schedule 40 PVC pipe. Length does not have to be precise, it will just determine the distance between the two rails. You'll want a minimum of 2" to allow for gluing to the fittings.

Cut the 1" PVC pipe

Step 3: Drill the Connection Holes

  • CAUTION: When using a hole saw with PVC, turn the drill to reverse before drilling the hole. Without using reverse, the hole saw teeth will quickly dig into the PVC and lock up the drill, which at a high enough speed could injure your wrist! Please be kind to your wrists and use caution in this step!
  • On one 50" section of square tubing, use the 1.75" hole saw to drill a hole on each end with dimensions as shown.
  • On the other 50" section of square tubing, drill a 1.25" hole on one end and a 1.75" hole on the other with dimensions as shown.

Drill holes as shown Drill holes as shown Drill holes as shown

Step 4: Drill the Plant Site Holes

  • Note: What's crucial about this step is to make sure your square tubing is oriented correctly. In Step 3, you drilled holes for the connecting tubing, to connect the two square tubes to one another. This means you'll want those holes (drilled in step 3) to be facing each other before drilling the holes for your plants. The two holes on the right side should match when each rail is rotated since they will have a connection between them. See the pictures below:

Drill holes as shown Drill holes as shown

  • Rotate the PVC to the next side with no drilled holes (drilled holes facing each other, sandwiched in the center)
  • Mark each plant site hole location with a permanent marker. Below is the hole pattern we've used, with the interior circles representing the holes and the exterior circles representing the outside of the lip of the net cups.

Drill holes as shown Drill holes as shown

  • Using a 1.5" hole saw with the drill set to reverse, center the drill directly on the mark you just made, and carefully drill out each hole.

Drill holes as shown

  • CAUTION: Be careful when cutting holes very close together as the PVC can crack. This happened to us once, as you see in the picture below. It's not unsalvageable (we just used a small amount of super glue to fix it), but it's not ideal. Just go slow and add gradual pressure as you're drilling.

Be careful of cracking

  • Once all holes are drilled, use a piece of sandpaper to smooth out the edges of each hole

Sand off edges

Step 5: Assemble the Connection Fitting

  • Using PVC glue, glue together the two halves of the connection fitting as shown. The connection fitting has a 1" NPT x Socket PVC Adapter Schedule 40 on each end, the 1" PVC piping you cut in Step 2, and a 1" Socket PVC Union in the center.
  • Apply a small amount of glue to the inside of each socket and to the outside of the 1" PVC pipe. Make sure that you've applied glue to the entire perimeter of the PVC pipe to ensure the glue seals completely. Then press together, twist one quarter-turn, and hold for 15 seconds until the glue takes hold. You can wipe away any excess glue at this point. You will need to do this 4 different times to connect the 6 pieces, as shown below.
  • The center union does not require glue, it can be screwed together to create a watertight seal. It also will allow the rails to be separated later on for cleaning or transport.

Assemble connection fitting Assemble connection fitting

Step 6: Insert the Bulkhead Fittings

  • Insert the bulkhead fitting into the appropriate hole on the side of each rail (the holes drilled in Step 3). The large threaded section of the fitting should go inside the rail. The two equal-sized holes on the right side will 1" bulkhead fittings with the connection piping between them. The holes on the left side will have a 1" bulkhead fitting and 1/2" bulkhead fitting with elbows to be used for inflow and outflow.
  • IMPORTANT: The flexible plastic gasket for the bulkhead fitting should go on the outside of the rail (see picture below). Then you shouldn't need any silicone for the bulkhead fitting.
  • Apply a small amount of super glue to the exterior threads of the fitting just before tightening the collar. This will prevent the collar from loosening later on.

Apply super glue

  • Tighten the collar as much as possible.
  • Insert elbows into inflow and outflow bulkhead fittings while further tightening the bulkhead fittings. Align the elbows correctly so that they point approximately 45 degrees downward toward the end of the rail. The inflow and outflow tubing will be connected from the elbows to the reservoir so the elbows should point towards the reservoir.
  • Separate the two halves of the connection fitting by unscrewing the union. Screw each half into the bulkhead fittings while further tightening the collar on the bulkhead fittings as shown below. Tighten the connection fittings using a large wrench or tongue and groove pliers to prevent leaks. The threads of each fitting are designed to lock together as they are tightened to make a watertight seal without glue (different from the threads on the bulkhead fitting collar).

Connection should appear as shown

Step 7: Attach the End Caps

  • Apply aquarium silicone caulk along the entire inside bend of the cap with extra in each inside corner. Apply PVC glue to the inside edge of the cap (adjacent to the silicone) and to the square tubing. Within a few seconds, press the cap onto the tubing and hold for several seconds to allow the PVC glue to begin setting. The glue we use begins to cure very quickly but can take up to 24 hours to completely cure.
  • It is very important that silicone is spread along the entire inside bend and corners of the cap to prevent leaks.

Apply silicone to end cap

Step 8: Connect the rails

  • Assemble the connection fitting by screwing together the two halves of the PVC union

Connect the rails as shown Full assembly

Note: Inflow and outflow tubing is explained more in depth in the Reservoir article so you don't need to take care of that now.

Step 9: Celebrate

  • You did it! You completed Part 1 of building your own hydroponics system. Now go pop some popcorn and high five yourself for a job well done. Now that you've got that under your belt, it's all downhill from here.

When you're ready for Part 2, click here to set up your Support Structure.