Building a Simplified Hydroponics Greenhouse in the Pacific Northwest

Jayne and Gary wanted to start a small hydroponic greenhouse operation to grow their own food and provide some produce for family members and for sale.

They first had to purchase and build a greenhouse. After shopping the market they settled on a kit form of greenhouse that was 30 feet wide and 48 feet long. They purchased the kit from Oregon Valley Nursery and the parts were delivered to their site, which is right behind their home.

First they had to level the land. Since Jayne’s son in law has his own cat and landscaping business, they had help in the process. Jayne points out that it is important not to dig out the land and make what will later be a giant puddle. The land was leveled and then graded to provide a slight slope to the back of the greenhouse. Then holes were dug for the supports, which were two inch steel quonset style pipes held in tension for the greenhouse walls. After the holes were dug for the supports, the supports were placed and cemented into place. Gary and Jayne did this by hand, and then had to cut the supports down to fit.

Once the structure was in place, they covered the greenhouse with two layers of plastic. A small air pump was used to provide a layer of air and insulation between the two layers of plastic. While this type of cover is inexpensive, it has to be replaced approximately every three years. An advantage is that the air insulation reduces heating and cooling costs when compared to glass or single wall fiberglass houses. Then, ends of the hut style greenhouse were covered with a clear poly material. The kit included a vent fan for cooling the greenhouse and removing humid air, and a 200,000 BTU propane heater.

Gary and Jayne researched several hydroponic systems and were intrigued with the simplified hydroponics systems used in developing nations. They were interested in the hand pour simple hydroponic systems primarily because of their reduced energy use.

“We had looked at systems including NFT and larger greenhouses, but they were expensive and did not seem to meet our needs. We were hesitant because we also were not sure how it worked, and most systems seemed to depend upon electricity. We are a long way from the grid and cannot depend upon electricity.”

“We were also concerned with how much water the hydroponics would take, and wanted to use a system that recycled its own water. We rejected any systems without recycle, and that included many.”

Gary explained, “Table growers are hand poured with nutrient every day, and all excess nutrient is drained from the bottom and then used the next day. The systems met my own criteria of recycling water and low power use.”

“A contractor built seven wooden table growers for us using the plans in the Home Hydroponic Gardens book but he adapted the original plans to include table braces. We also built the tables with two by six inch boards for legs to strengthen the tables. We expect to use them for as long as 20 years, and do not want to be replacing tables.”

They waterproofed the wood beds with a six millimetre thick black plastic liner. Gary and Jayne purchased rolls of black plastic in 10 by 25 foot rolls but the plastic sheeting was full of holes and particles that were embedded in the plastic. It proved inadequate for the bed growers.

Jayne wanted a material that would last longer than the estimated four years for the black plastic sheeting. They found a pond liner that is guaranteed non-toxic and fish safe. It is manufactured by Firestone and sells for prices from 42 to 59 cents per square foot. The liners were purchased from a 15-foot wide piece, cut into squares 6 foot by 7.5 foot.

The pond liner material is guaranteed for 25 years. When placing it on the grower it was noted that it was very difficult to puncture. The cost estimates per grower were between 17 and 21 dollars each depending upon the cost for the pond liner. Firestone also makes a pond liner, which is not fish safe (or hydroponic safe). It does not have the stamped fish logo on the liner.

Gary and Jayne then needed to create a drain hole in the growers. The original instructions called for using 5/8” plastic tubing through a drain hole, and then melting the black plastic liner to the tubing. This proved to be a problem with the new pond liner, and also melting the tubing and plastic sheet could have formed a weak connection, not made to last.

Gary found electrical connection parts that could be placed on each side of the grower and screwed into place. The one connector was placed through the side of the grower from the outside. The pond liner was cut in a very small hole, about 12 mm (1/4”) and then the pond liner material was stretched over the fitting. A rubber o-ring was placed over the fitting and pond liner and the second piece was screwed over these parts, fitted snug against the rubber O-ring. In this way, a drain was formed that can be used and then unscrewed for clean out, or a cap can be screwed on the end to make this a floating bed grower. The growers were then leveled and placed on a slight slope to facilitate draining.

Jayne completed stapling the pond liner to the outside of the grower, and then filled one bed with perlite media and one bed with coco fiber. The bed growers required about eight cubic feet of uncompressed coco fiber and eight cubic feet of perlite.

Then each bed grower was watered with nutrient solution. Jayne mixed her first nutrient solution according to the instruction on the labels and in the book. She used a five-gallon container of this for each grower and then wet down the beds until nutrient came out the drain hole and flowed through the plastic pipe to the container below.

Once the table growers were set up and watered, Jayne planted her seeds in the perlite bed and strawberry runners from her garden in the coco fiber. The coco fiber was an experiment to test the new growing media in the table growers.

Gary and Jayne also set up three floating bed growers for growing lettuce. In these growers the liners were stapled to the wood of the bed and no drain holes were drilled. Since large pieces of Styrofoam were not available they bought smaller pieces of Styrofoam one-inch thick white, and then cut that to size for the beds. The pieces were cut to allow about a quarter-inch opening between the bed and the floating part.

The pieces of foam were laid out in a pattern to allow for two sizes: A mid size about 3.5” apart and a grow-out bed of 6.5” for full-grown lettuce. We laid out holes to do one mid-size bed (three sheets) and two large size holes. The concept was that the seedlings would be placed in the mid size grower for about 15 days and then transferred to the larger hole growers for the next few weeks.

They tried to drill the holes with an electric drill and this tore up the Styrofoam in the bottom of the sheet. Then they heated up the end of a one-inch metal plumbing pipe and used this to cut the sheets. This worked well and they rapidly had the holes cut for the three bed growers. All the holes were sealed from the heat and clean on top and bottom.

They filled one floating bed grower with 35 gallons of water and measured the water level in the grower at 2.5 inches. This appeared adequate for the level of the floating beds. Later Jayne and Gary will purchase household cellulose sponges to cut into one and a quarter inch squares to hold the lettuce plants in the grower. First the lettuce seeds needed to germinate in the seed grower.

They also set up two gravity fed bucket lines for hydroponics. These lines were based on using plastic buckets with drain holes placed three and a quarter inches from the bottom. The five-gallon buckets used were purchased from a plastic supplier and guaranteed food grade.

Food grade in plastics usually means a polypropylene bucket that contains no recycled materials (virgin materials). Most food grade containers are white or clear. The clear are not suitable for hydroponics because the light allowed in the container will allow algae to grow. The white also can allow algae to grow, but much less than clear, and the white color is suitable for reducing the heat from sun. Most black buckets should be avoided because they may contain a dye that is not approved as food grade.

The three and a quarter inch drain hole was determined by pouring one gallon of water into the bucket and measuring the level of this amount of water in the bucket. When media was added, the bucket contained about one gallon of water, both under the drain hole and above in the media. This was estimated to be the amount of water required for a plant growing in a five-gallon bucket.

The buckets were all drilled and a manufactured 5/8” grommet was used with a barbed straight pipe. You can find this fitting at most hydroponics stores. A smaller drain hole can also be drilled and filled to smaller parts such as 3/8”. The straight barbed pipe is used to reduce the amount of media leaving the bucket. Additionally, a small filter can be created for media that can flush out of the system.

The buckets were all designed to be fed from a 35-gallon reservoir of nutrient water. To accomplish this, a drip irrigation system needed to be designed to feed the estimated 24 buckets that were to be watered in the gravity fed system.

Twelve buckets were placed against the north wall of the greenhouse. These were designed to be used for tomatoes or other vine plants to be supported by trellis or cable supports above. Part of the reason to grow these against the north wall is that when they vine against the wall they will not block the sun from the other plants. The greenhouse is located at about 45 degrees North in the northern hemisphere and the north wall is the least important for emitted light.

A row of buckets was also placed in front of the wall buckets and these will be used for taller bushy plants such as eggplant, bell pepper and tomatilla. Each bucket will contain one plant.

It is in fact difficult to predict the amount of water used by the bucket growers because the plants growing in the buckets will be of different sizes. For example, a single cucumber can take up a large wall space and use a lot of water per day. Also, plants will use more water during hot days, sometimes being twice as much as normal. A gallon per day of water is an average estimate that will have to be reevaluated, as the greenhouse is in operation.

Another reason that it is difficult to estimate daily water use on a gravity fed system is that each bucket will have its own valve-controlled water emitter to drip water. If these are turned up too high, much of the water will go through the bucket and out the drain hole. In this system, all drain water is gathered and piped to a bed grower on the ground that grows a single crop such as watercress or onion. If a lot of nutrient water is drained each day the drippers should be turned down.

The drain holes in the buckets were designed to serve as fault tolerant systems reducing the chance of flooding the plants. In operation, the drippers can be turned to just under the drain hole and this will reduce the amount of drained water. Unfortunately, this is often difficult in actual conditions in the Oregon Mountains where weather can change from sunny to cloudy conditions often in a single day.

It is not advisable to recycle the excess drained water into the barrel of nutrient water because there is a possibility of introducing a disease to all the plants. It is better to drain the waters to a single grower (or two) growing a resilient plant such as watercress or onion. Onion works better in systems that have very little drained water and watercress works better in systems with more drained water. If a disease should occur, at the worst the crop of onion or watercress would have to be composted, but the bucket growers would not be affected.

Jayne and Gary have set up two sets of gravity fed buckets against their north area of the greenhouse, and may find they have room for more as the plants grow. The systems require buckets, a barrel, and drip irrigation equipment. The drippers in this system can be a problem because they can clog from the hard water characteristics of hydroponic nutrient water. Some of the companies such as Netafin, are familiar with hydroponic use and can recommend drippers that have larger orifices which are less likely to clog.


Gary and Jayne have about $10,000 invested in their venture so far, with almost all of that devoted to setting up the greenhouse. The costs of the hydroponics will be between $800.00 and $1400.00 depending upon the costs of the grower construction. This cost is also based on using the more expensive pond liner that will add about $300.00 to the cost of the grower setup.

Jayne likes the idea of the greenhouse, partly because her hours will be flexible. She can go out to the greenhouse in the middle of the night to implement something, or not have to work a steady required 40-hour week. She also loves plants so setting up the greenhouse is actually a business that is one of her passions.

Gary also chose to build the greenhouse because he desired to become more self-sufficient in meeting his own food needs. “I believe that the best thing a person can do for society is to become independent. Reduce the need for fossil fuels and electricity and grow your own food. Think what it would mean for resource use in the United States if every family had even one bed grower like this. Think of what it would mean just for the transportation costs alone.”

Gary and Jayne have also expressed an interest in becoming a part of a support group to help others set up their own greenhouses and simplified hydroponic garden in developing countries. Their experiment is a blueprint fuelling their future endeavours in helping others feed themselves.

“If we cannot sell the food we produce we always have the option of giving it away to those in need. We have family members that would be very happy to have produce that is pesticide and herbicide free and fresh.”

Peggy Bradley is the Executive Director of the Institute for Simplified Hydroponics and co-author with Cesar Marulanda of Home Hydroponic Gardens. This instructional guide to hydroponics written in English, with both French and Spanish translations.