Aquaponics Wall of Salad and Fish – by Eve Sibley

Author: World Food Garden Founder and CEO, Eve Sibley

Last month I had the exciting task of building a vertical garden on the southeast wall face of an infinity pool at the Anamaya Yoga Resort in Montezuma, Costa Rica.

Eve Sibley's Wall of Salad, Costa Rica Style

The plan was to make a vertical aquaponics garden that would be fed by a fish tank which we would build in the room underneath the infinity pool. Though seemingly complex, Aquaponics is really pretty simple- the hardest part about the whole process was sourcing the supplies we needed from around the rocky, hilly, muddy, landslide terrain where roads often close, ferries stop running, and supply stores say manana a lot which really means hey maybe. But fortunately Ricardo and his brother from the Cobano Coopertiva and Adriana and Rainer from the hardware store were on my side energetically putting in phone calls to farmers and stores near and far, transforming my broken Spanish descriptions of the products I needed into a Getting Things Done (GTD) functionality.

Aquaponics, like hydroponics, is when you use a soiless substrate to grow plants and cycle nutrients through the soiless grow-beds. When you are growing a Hydroponic garden you are usually adding nutrients in the form of chemical fertilizers that you have to buy from the store. However, when you grow an Aquaponic garden, you are adding nutrients to the grow bed by cycling water that contains fish-waste through the bed. Fish excrete Ammonia and plants eat nitrates. And as long as you create the right kind of atmosphere, i.e. pee in the fish tank a week before you add fish ( I learned most everything I know from my friend Dr Dave at Earth Solutions), you will attract the real managers of the aquaponic garden- the Nitrifying bacteria. These guys break down the ammonia into Nitrites and Nitrates and then the plants eat them. Its called the Nitrification Cycle. Microorganisms are rad. Anyway, the Aquaponics process results in a nice symbiotic cycle of the fish feeding the plants and the plants in turn cleaning the water for the fish.

Costa Rica infinity edge pool

So after my experience building the Wall of Salad last fall at the CouchSurfing Collective, and also after beginning to learn about Aquaponics through a cool mini-kit from Earth Solutions, I wanted to see if it would be possible to bridge these concepts into a Vertical Aquaponics system. Being a new sustainability-oriented hotel that honors most things cutting-edge, Geoff and Joseph from the Anamaya Resort were totally down for my experiment to happen there.

The process was slow in the beginning as we deliberated over what materials to use for the planters and soiless grow-bed substrate. My strongman boyfriend Walker spent hours chopping apart coconuts, that we had collected for our sacrificed shrunken head business, in order to get the fiber substrate until some further experiments proved that coco-fiber would continuously dye our fish water red. And though apparently the murky red water isn’t so much a problem for the fish, it would not make fish-viewing a very inspiring occasion for hotel guests.  For the planters, we needed something that could withstand heat but would keep the plant roots from getting too hot, and that sturdy enough to stand up against the elements but not too heavy that we couldnt attach it to the wall. After a long process that included hitchhiking to faraway pottery towns, brainstorming pages of designs with Walker, visiting a couple terracotta factories, and then playing around with macramé, beeswax and gourds, it was decided that we would buy terracotta covered plastic planters, modify them to suit our purposes, and attach them to the wall with shelving racks. Anamaya’s Joseph thought it was more important to prove the concept than to go all-out-extravagant in the aesthetics.  In the end, I think the plastic planters aesthetically hold their own in an urban-sharp-landscape kind of way.


I smuggled in some non-invasive organic vegetable seeds,  (list at bottom),  including many  Asian greens that Geoff suggested would work well in the Costa Rican tropics, and got the seedlings going in this mini greenhouse while I worked on the wall.

The concrete  wall was not totally waterproof and so after a rigermarole of locating a non-toxic aquarium safe concrete sealer in Costa Rica, Ronald showed me how to seal the tank. Walker was back in the states by then and couldnt help so I got down to business and took a couple days to seal concrete (2 coats each side of wall) while my thoughts went back and forth from feeling like a badass to remembering something that my mother had said to me that her mother had said to her which was to Never learn anything that you don’t want to get stuck doing for the rest of your life. But I also learned how to cut PVC and drill into concrete walls on this trip and quite like having those skills. So to expound on my foremother’s wisdom I would add- You can always PRETEND you have never done it before )

Anyway, wall finally sealed, planters retrofitted to flood and drain into each other, (some day I will share pics of how I did this part, but I promised a friend I would keep his trade secrets secret for now), gravel washed, planters filled with gravel, aerators hooked up, pump hooked up,  and 3 days before my trip ended I came in to find the tank almost empty! Thinking something was wrong with the way I had applied the sealer, and realizing there was not enough time to re-seal, I was almost resigned to a 1/2 finished project which I would have to come back too later on, maybe in  the fall, if I could find the time/money. But this is just when I learned an exciting fact about physics- the power of self siphoning! When I had checked the pump the day before, everything had been working fine and so I had turned it off and walked away. BUT I had left the HOSE connected to the pump and hanging over the tank wall. Because there had been no chance for air to enter the hose after I had used it with the pump, a natural vacuum had been created and caused the tank to self siphon in my absence.


Realizing this less than 30 hours till I had to catch the bus to the ferry to the airport to the states, the project was back on. I refilled the tank with water, prayed that the 6 inches of water at the bottom and the layer of lava rock and gravel had a strong enough colony of nitrifying bacteria going to welcome a family of fish and headed out to a nearby farm to pick up the tilapia.

Tilapia sourced, and finally  it was my last day and time to get them in the tank and transplant the seedlings. I performed a couple transplant demos for Alex, Oscar, and Joseph, and then rushed to catch the last bus out of town.

Unfortunately I had a decent video of the garden with the fish swimming around and the planters flowing into one another, but it was on my iphone which I lost last week while dancing with Walker at an Afrobeat club in San francisco. Since leaving Anamaya, Joseph has taken  the garden on as his pet project and gets to do the real nerdy fun biology stuff like, watching it grow, feeding the fish, testing the PH and making any necessary changes if a fish or plant dies. Maybe Joseph will send us some updated pics as the garden progresses.

joseph gardener

Seeds we used:

Matt’s Cherry tomato
Tah Tsai
a variety of Pak Choi
Japanese Giant Red Mustard
Thai Yellow Eggplant
Malabar Spinach
Mexican Tarragon
Kamo Eggplant
Lao Purple striped eggplant
Dwarf Choy Sum
Sword Lettuce
Garlic chives
Mignonette Bronze Lettuce
Genovese Sweet Basil
India Spinach Beet
De Rapa Broccoli
Okahijiki, land Seaweed
Long Choy Sum

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