Today’s Build Day was supposed to be our grand return after our break for the winter. Mind that I said “supposed to.” Unfortunately, it was reported that the winds of the winter had done quite a number on the LEAF garden. The roofs of the several greenhouses were blown off, including ours, and there was general damage all over the site. The most serious damage, though, was that some electrical equipment was exposed to water, which forced the garden manager to shut down all power in case it happens again with possible forecasted rains. It sucks that our return is delayed, but we will come back even more prepared next week.

Grow with the flow!

Recovering from our failure from last Build Day, we were ready to tackle the shrink wrap cover again.

Because the heat contracts the wrap at just the location it is applied, it pulls the surrounding parts of the shrink wrap in. The process of properly shrinking around the whole dome is quite delicate as it requires us to move the gun up and down and around its surface to spread the heat as evenly as we can. We also have to make sure to keep a certain distance away from the surface of the shrink wrap so that it is heated enough to shrink, but also not so close that we burn a hole in it.

Keeping this in mind, we began our second attempt at covering our greenhouse. We bathed the shrink wrap in heat, making sure to keep everything as steady as possible and, in the end it wasn’t perfect, but we succeeded.

As we were finishing the shrink wrap up, we secured it by stapling it to the walls with pieces of cardboard overlaid. This lets the staples hold the shrink wrap down, while not tearing it because of the increased surface area of the cardboard. With this done, we could begin work outside the dome, but that will be saved for after we take a break for the winter.

Grow with the flow!

Today is an exciting day! We finally get to cover the greenhouse with the shrink wrap. For any greenhouse to work, you need insulation to help stabilize the temperature. We chose to use shrink wrap because it allows us a greater degree of freedom when covering our uniquely shaped greenhouse.

The way shrink wrap works is that it reacts to heat by shrinking in the exposed area. We had to unpackage the shrink wrap kit, which came with a heat gun and a giant length of shrink wrap. It was so large that we needed at least 5 or 6 people just to unfold it so that we could measure it to see how much we had to work with. It was quite large, so we should be able to get 3 tries out of it before we run out. The heat gun is more reminiscent of a flamethrower with its long body, big handle, and the fact that it connects directly to a propane tank.

We cut off some small pieces to test how quickly and much the heat gun shrinks the wrap and then once we felt comfortable, we attempted to clothe the greenhouse. We had to make a large cut through the length of shrink wrap and with that piece, begin to pull over the dome. We wanted to be as secure as possible, so everyone but the heat gun wielder held the shrink wrap in place. Things were going well, the shrink wrap was tightening around the dome, but then disaster struck; there was now a hole in the wrap. We had to abandon this piece as the insulation has to be airtight. The day was coming to a close, so we had to try again next time.

Grow with the flow!

Build Day this week had a performative twist. Aman, our project manager, alerted us to the ACWD WaterClips Student Video Contest. This is a contest where middle and high schoolers send in videos about chosen topics under water conservation to the Alameda County Water District.

While some of us carried out tasks like dismantling planter boxes, a few others tested their speaking skills through practicing for the ACWD contest. Of course we didn’t leave the labor to one group and rotated people periodically.

Overall, recording for AWCD was a blast and educational experience. Being able to talk coherently, whether 1-on-1 like in an interview or a casual conversation or to a group like in a video or a speech, is an important skill to have.

Grow with the flow!

When you create a system, such as our hydroponics greenhouse, you want to plan it out with a model first. For our model, we will just be looking at how much food the hydroponics system should theoretically be able to produce in a year. First, we need to find the value of all our variables for the model, which are simply the number of lettuce and growth period. 

We will be producing butterhead lettuce of which the growth period is about 50-60 days, so let’s just call it 55 days. Now, we can find the number of lettuce by dividing the length of our pipe by the growth space of one head and then multiplying by the amount of pipes. If our pipe is 52 inches long and a head of butterhead lettuce requires 8 inches diameter to grow, then we can grow about 6 heads per pipe, which multiplied by 3 pipes is 18 heads of lettuce. 

With the number of lettuce the system can grow at once and the growth period, we know that it can grow 18 heads every 55 days. Since there are 365 days in a year, we reach the conclusion that we can grow an average of 120 heads of lettuce per year.

Grow with the flow!

Today, we deepened our understanding of hydroponics by creating a scaled-down version of our hydroponics system. Using smaller PVC pipes with pre-drilled holes, we set out to model the entire system. This allowed us to visualize and analyze the flow of water throughout the entire completed system and how efficiently water would reach each plant within the setup.

Since we had smaller PVC pipes with holes in them, we decided to model the hydroponics system to see how exactly the water would flow and how it would provide water to the plants in the system. After figuring out where all the pieces go, we assembled the system and began running water through it.

By making this model, we gained a much clearer understanding of how the hydroponic worked. We learned about the importance of maintaining a consistent flow rate and ensuring that the holes in the PVC pipes are correctly positioned and sized.

Keep calm and keep growing!

Today, we focused on furthering the greenhouse, making a proper entrance for it, and starting to put together the hydroponics system. To start, we had to make a doorframe to eventually put to the door in. To achieve this, we used the left over planter box wood and cut it to the measurements of the door. Once the frame was put secured to the dome, we had to secure the door into the frame. We used screws and hinges to attach the door to the frame, successfully making a proper entrance to the dome. Finally, we started the hydroponics system. We used chains to allow the pipes to be hung midair so less material had to be used in the system. To create the pipe we used a PVC pipe, drilled evenly space holes, and glued caps on both sides to keep the water inside. Then, we drilled two smaller holes on the left side and the right side of the pipe, one for intake, and the other to flow water into the next pipe. Finally, we attached the pipe to the chains.

Keep calm and keep growing!

Now that the dome is secured to the inner wall, we needed to trim parts off to make way for the entrance. We essentially removed the pipes that were above the 10th edge of the dome up to the top pipes, which we didn’t touch. Since we were going to append a rectangular corridor to a geodesic dome, we cut some of the connecting pipes to fit.

At the same time, we had a group working on the door frame. We measured out the dimensions of the door and gave a slight gap for the inside measurement of the frame. We also cut out a large roof piece that attaches to the frame and rests on the dome, a horizontal support at the end of the corridor, and a diagonal support for each side.

Once all of these were screwed in place, the structure was sound and we could install the door too. We needed two people, one inside and one outside, to hold the door up as it hovers above the frame, while another person screwed it to the door hinge. With all of this work, the main structure of the greenhouse was done.

Grow with the flow!