Building a Simple Hydroponic Rail System
Looking for a hydroponic system that is both easy to build and productive? Yeah, me too.
My goal was to design a rail system that takes less than 2 hours to build and doesn’t require PVC glue. This isn’t my first attempt. I’ve been using indoor hydroponic rail systems to grow produce in my home for many years now. They are very productive and a great way to have a steady supply of produce all year long, even in difficult climates.
Hydroponic Rail System Design
The design is simple and similar to rail systems I’ve designed in the past. A pump circulates nutrient solution into the first rail and back out the second rail, forming a loop. Additional rails can be added to increase the growing capacity. Seeds are planted into a seed plug and placed inside a net cup, which rests in the rail. The first rail is set up to have the water level high enough to keep the seed plugs moist, allowing plants to grow from seed to harvest in the same system. This system works great for leafy greens and herbs, and can also be used with fruiting plants like strawberries or dwarf tomatoes. Large plants are more difficult to grow in a rail system like this since they require vertical support and lots of root space.
1. Cut the Rails
To build this system, I started with a 4” diameter fence post and cut it in half to form two rails approximately 4 ft long.
2. Drill Connection Holes
For making connections, I drilled 2 holes on the inside face of each rail - one on each end. 1 hole for the entry, 1 hole for the exit, and the other 2 holes for connecting the rails together.
3. Drill Plant Site Holes
To create spots for each plant, I drilled 1.5” holes in the top of each rail. The holes are spaced closer together for smaller plants, and farther apart for mature plants in order to make the best use of space and grow as many plants as possible. This will also allow me to have a continual harvest, since there will always be several mature plants ready and smaller plants to take their place once I harvest. I sanded off any sharp edges to prevent damage to plant roots.
4. Add Connection Fittings
I installed bulkhead fittings into each connection hole from step 2. Bulkhead fittings are nice because they are easy to tighten down and don’t require glue. They can also be easily disassembled if needed. For the inlet and outlet, I threaded elbows into the bulkhead fittings. These allow me to connect tubing to and from the nutrient reservoir. On the other end, I connected the rails together using a riser, which also threads into the bulkhead fittings. This is simple to disassemble later on when I want to move or clean each rail individually.
5. Attach End Caps
Once all the connections were ready, I used aquarium silicone to attach end caps to both rails to create a watertight seal. After letting the silicone cure and washing the rails, this system was ready for plants!
6. Set Up and Start Growing
I set up this system on a shelf under a grow light, and within several weeks I had a full garden of lettuce growing in this rail system!
If you want to follow along with what I built, I created a free guide that shows each build step, the hole layout and the materials you will need to build this system.