Here is the first of three videos on how the aquaponic system is assembled in the geodesic dome. This first video recaps some of the installation that was done during the dome construction and shows a general overview of how the entire system operates.
Hi, I’m Rob Torcellini
This video series will show you the various details about how I set up the aquaponic system in the geodesic dome greenhouse.
This first video, I’ll explain how some of the components were installed during the dome construction. I grouped the video sequences by the component, not in the chronological order of when they were installed.
First is the central sump tank. This tank is used to catch all the water that is draining from the grow beds and a pump returns the water to the main fish tank.
While the foundation hole was empty, I built a brick wall around the tank. The wall leaves a gap around the tank so that it can expand and contract when the temperature changes. If this wasn’t installed, eventually backfilled dirt would crush the plastic tank. The end of each pipe draining into the sump has an elbow to help swirl the water inside the tank, which will help to reduce sediment buildup.
Also while the foundation hole was empty, I installed a large sump tank which is used as a buffer to compensate the changing water levels in the grow beds. The water from the fish tank drains into this tank and then pumps the water into the grow beds. This tank holds about 500 gallons of water and has a cone bottom, allowing sediment to work its way down and sucked out by the pump.
This tank also has a block well-housing built around it to protect it from getting crushed. This is a view of the central sump and buffer sump wells while they were being backfilled.
There is a network of drain pipes that are buried under the floor. These are used to collect the water from the assortment of grow beds that are throughout the dome.
The drains are 2” lines and are set at a slope to drain the water into the central sump. There are extra drain inlets that come up to the floor which will not be used, but at the time I installed this, I had not decided on the final layout of the grow beds.
All the pipes are backfilled with sand to protect them from damage. This allows me to easily dig them up if any maintenance needs to be performed. After I lay down the final floor, the drain pipes are cut flush with the floor. If any dirt or insects fall into the pipes, they will just get flushed into the sump tank. Here is the final view of the drain pipes with the central sump tank.
The last component is the main stock tank. This is placed in the northern section of the dome to help minimize light and algae growth. The tank is a scrap tank that I salvaged and it had a bunch of fittings that needed to be capped. After leveling out the area with a sand base, the tank slid right into position. While I was installing the drainage pipe, I buried a scrap section of 4” pipe between the sump and fish tanks. This allowed me to run the pump and electrical lines between the two tanks under the floor. Since the tank was so tall, I wanted people to be able to easily see the fish so I installed 2 windows.
This is a functional overview of the entire system. Water from the fish tank overflows into the buffer sump tank. It is constantly pumped, along with any solids under the floor and into the grow beds. The line to each grow bed has a valve to help regulate the flow. There is also a line that feeds back and shoots water back into the fish tank to help aerate the water.
Using bell siphons, the grow beds continuously flood and drain. The inner beds drain directly into the sump tank, while the outer beds drain into a raft system (not shown), which then drain into the sump.
There is a float switch in the sump tank that pumps the water out of the sump and back into the main fish tank.
The large sump tank is use to maintain a consistent water level in the fish tank. Since the levels in the grow beds and central sump tank are constantly changing, that difference in volume has to be offset elsewhere. Not only does this help with the water levels, it adds additional thermal mass to help keep the water temperature from fluctuating each day.
In the next video I’ll detail the plumbing installation. Thanks for watching!