Going Vertical
Word is spreading about just how fresh, delicious, and biosecure our produce from the auqaponics greenhouse is. With the new farmer’s market at NorthLakes Community Clinic in Hayward, along with the 30 extra CSA (Community Supported Agriculture) share memberships through their grant project, the system simply does not have the growing power to currently meet these needs plus our regular CSA clients and culinary and shopping needs at Farmstead Creamery.
As Nelson and Pade (the company that designed our aquaponics system) has perfected their technique, they’ve learned that the quantity of fish we raise can actually support more plants than initially included in our design. The traditional method for increasing growing space is to add another bay to the greenhouse and build more rafts and media beds.
But building another bay is incredibly expensive, let alone the ongoing costs of heating all that extra air space through the winter. What if there was a way to utilize the current space we already have more efficiently? Some folks do aquaponics in warehouses, all stacked up, so there must be a way!
Steve and Ann sunk their teeth into researching options and found some folks who were suspending NFT (Nutrient Film Technology) channels over the top of raft beds. This adds a second layer of growing space while utilizing the same circulating water from the system. It would mean pulling the current grow lights (used to help the plants mostly in the winter months) up higher and suspending new water-resilient lamps below because the channels block most of the ambient light.
We do have some NFT channels at the back of the greenhouse, but they are floppy and difficult to clean and handle. The idea of suspended channels (which are lightweight) sounded good, but the product at hand was less than ideal. That’s when we found a company in California (American Hydroponics) that made one-piece NFT channels they said you could drive a truck over and they’d still be good. No noodle flopping, no messy PCV ends to glue. They came ready to go with only minimal manifold assembly, which fit our time crunch perfectly.
The new grant program CSA shares had already started, and we were feeling the production pinch before the gardens came into their season. It was time to get going vertical with our growing potential off and running! Mom and Steve put in endless hours with suppliers, figuring out a frame design from pipe tubing to suspend the NFT channels over the raft bed at the proper height while also supporting the lights below.
As the design process progressed, we ordered some of the channels right away with a tighter hole spacing on top to build an NFT nursery over our current nursery table for starting seedlings and allowing them to grow up a bit more before moving out to the main system. This would allow us to shorten the time each plant needed to grow in the main system, creating a faster turnaround (more efficiency of existing space) as well as give us a bit more buffer with the plants we had ready to rock and roll in the new setup but had no place yet to go.
In NFT channels, water flows in a thin trickle across the corrugated bottom of the closed tray. Plants sit on the bottom in their grow cube, with their leaves sticking through a 2-inch hole at the top. The shade from the rest of the channel keeps the roots below happy and cooler, while the leaves are free to soak up the sun and breeze that comes in through the screens on the greenhouse sidewalls.
All this is accomplished without the use of any soil, which means that the plants are incredibly clean when harvested. Cleaning the new channels has also proved very easy too. After gently teasing out the little plants, I pick off any dead leaves that were left behind, hose it all down, spray with a sanitizer, and am ready to plant again! No weeds even! I like it…
Then came the huge project of installing the main system of NFT. Dave Arnett, our electrician came with his crew to move and hang lights, as well as move some of the fans. The framing is taller than me and certainly changed the architecture of the space. The new system spans half of the length of one of the raft beds (though it is a couple feet wider), so we placed it over the side where the raft plants are younger and therefore shorter.
The frame is also built so that the plants can still be pushed underneath towards the side where they are tall and mature (like a really slow conveyor belt). This meant that the NFT channels were able to be built as low as possible, or I’d never have been able to reach them at all!
Now it’s all up and running and planted with 7 varieties of lettuce. Yay! What a huge project, but what an exciting vertical expansion for our greenhouse. We have enough channels to build a second one, but no framing or lights yet. We’ll run this one for the summer since we have the added produce from the garden, and we’ll see if it’s time to add the second segment in the fall.
The system we just added provides the same amount of growing space as an entire raft bed! Here’s to a whole mess of yummy aquaponics lettuce for everyone! See you down on the farm sometime.