Building Our First Hydroponic Greenhouse

We officially made it through our first summer with the hydroponic setup and have torn it down for the winter. We had several challenges and learned a lot through the process. Here is what worked well, what we'd do differently and our keys to running a successful hydroponic setup!

Building a Thriving Hydroponic System

We were amazed how effective our hydroponic greenhouse setup was. It was straight forward to build, easy to manage and exceeded our expectations! Plus, we loved how clean it was - no dirt and no issue with root diseases. We even accidentally almost killed our plants twice this year and still received a great harvest of vegetables throughout the summer. So, the best news we found is hydroponic systems are very durable and plants can bounce back.

​Looking back after our first year, here is what we'll do differently the second year and the keys to building an even better system:

1. Use large enough tubes! Plants grow enormous root systems that can plug the water flow.

2. Spacing is key for plant growth, air flow and harvesting. Plan on more space between plants.

3. Consistent and reliable power for your pump. Sounds obvious but ruin your hard work.

4. Use the right nutrients. This is key to fast starts and big returns!

Full Hydroponic Setup For $81

This system worked incredibly well, except using too small of tubes. I'll get into that challenge below. Our starts sprouted incredibly quick and grew very fast. Our tomato plant starts had much thicker stalks then our outdoor starts. Getting the seedlings early nutrients and consistent water flow was key. After 3-weeks, our hydroponic plant starts were 3x-4x larger than our outdoor plant starts.
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We built our hydroponic system with a 55-gal plastic drum, 24-watt (800 GPH) pond pump, 3/4" PVC water pipe and 2" tubing for the plant rows. That's it! The overall system is very simple and inexpensive to build. It was based on a gravity return flow, where we pumped water to high-side of the PVC and let the water naturally flow to the low-side return.

Each 2" PVC pipe section was 8' long with twenty 2" holes drilled in them for the plants. We used 2" Pot Cups for Hydroponics and Jiffy Seed Starting Peat Pellets. Links for each on Amazon are below:

• 50 Pack Lightweight 2" Net Pot Cups for Hydroponics and Aquaponics

• Jiffy Seed Starting Biodegradable 42mm Peat Pellet Refills, 5 Pack (125)

• VIVOSUN 800GPH Submersible Pump(3000L/H, 24W)

We purchased the 55-gal from a local restaurant supply company on Facebook Market Place for $20 and sourced the 2" PVC pipe from a local builder with extra after a completed job. Overall, the entire hydroponic setup cost us $81.84!

Mistakes to Avoid and What To Do Different

We quickly realized our first mistake - using 2" PVC tubes that were too small. With a consistent flow of nutrients and water, the plants develop HUGE root systems. Several were 3+ feet long. Each 2" PVC tube held 20 plant starts, so the root systems very quickly filled the entire tube and blocked water flow.

This was by far our biggest challenge and maintaining water flow to all plants as the root systems took over. By July, roots had completely blocked some tubes causing the water to overflow and not reach other plants. Plus, overflowing water emptied our 55-gal water reservoir quickly. It no longer was a closed looped water return system and caused us to add more water throughout the week.

Improvement #1:
Use larger PVC tubes (4" at a minimum) or rain gutter down spouts. I believe the enclosed rectangular down spouts would be better solution. The 2" holes for the plants to sit on top of the channel were sufficient. A rectangular down spout would allow the water to nearly completely fill the tube without over flowing. It would also allow plant roots more room to spread out. The 2" PVC tube kept the roots tightly packed.

Improvement #2:
​Connect your water pump to a dedicated power source. Starting the summer we connected the power source to our RV outlet. A family member visiting for the summer needed to charge her electric car, so unplugged the RV. Without even realizing we had cut power to our hydroponics as well. It was a brutal surprise several days later when we walked into a nearly dead greenhouse. The plants hadn't been watered in several days. Thankfully they rebounded back but surly stunted our potential veggie growth.

We have already corrected this issue and wired a dedicated power supply in the greenhouse, so we'll avoid this issue in the future.

Improvement #3:
As mentioned, the plants grew much larger and faster than we expected. They quickly out grew the greenhouse and became too closely packed to see all the veggies. It was very difficult to harvest consistently and missed many veggies that we just didn't see under all the leaves.

Be sure to spread out your tubes to give enough room for your plants to grow AND for you to easily harvest.

Our plan next year is to start all our plants in the hydroponics; even the ones we will move to the outdoor garden. This gives us a few weeks head start, as our last frost is usually late-May. Then, once the outdoor garden is ready we'll move all our large plants outside. This include tomatoes, zucchini, squash, cabbage, kale and melons. These plants overran our greenhouse. We will keep the smaller plants in the hydroponics such as the peppers, lettuce, basil, onions and cucumbers.

That's it! We'd grade our first year running a hydroponic system at a B-. There are definitely things to improve but we grew a great variety of veggies that we harvested into late fall. We've torn it down now but I'm already planning our improvements to make in April when we start it back up again!