My wife is an avid gardener (and plant nerd) and I have an addiction to aquatics (fish nerd). I love setting up self-sustaining, low effort ecosystems for my fish. It can be surprising that these hobbies fit together nicely—symbiotically, if you will. Our hobbies come together in our backyard garden where we have a garden ponds, raised garden beds, and rainwater collection. We’ll walk through each of these items and discuss how they work together beginning with the garden pond.
Garden Ponds
Our middle Tennessee backyard is home to a small 800 gallon garden pond, with the deepest part at 36” so goldfish can overwinter without a heater. As any aquarist will tell you, one of the main reasons you do occasional water changes is to reduce the amount of nitrates in the water column. When debris fall in your pond or fish poop (goldfish are notorious poopers), ammonia is produced. Bacteria in the filter and on the pond surfaces turns ammonia in nitrite and then into nitrate. Too much of any of these chemicals will kill your fish. With a combination of live plants, and water changes, you can remove the nitrates—which is essentially a fertilizer. I good rule of thumb for an aquarium is to change around 10-20% of your water every week. For our 800 gallon pound, that amounts to 100-200 gallons each week that we pump out to our raised garden, flower beds, and herb boxes.
Square Foot Raised Garden Beds
We have two 4’x8’ raised beds used for square foot gardening. In short, square foot gardening involves arranging your plants into 1’x1’ sections in such a way that they benefit each other with their placement. A typical square foot of gardening requires 0.6 gallons of water per week. Quick back of the napkin math and we end up with around 30 gallons each week. The rest of the water is pumped out the flower beds in the front and the herb box hanging off the deck railing, which overflow to the blackberries and strawberries underneath. We end up running our pumps for around 4 minutes a day to pump out 150 gallons on fertilizer-rich fish water.
Rainwater Collection for Garden Ponds
In order to keep our plants thriving, we pump out 150 gallons every week from the pond—we call it fish water. But, how are we refilling the pond? We used to refill the pond off the tap through a dechlorinating filter to remove the chlorine and chloramine. A DIY method for rainwater collection involves downspout diverters and 55 gallon food grade plastic barrels. Roofs collect a TON of water. The roof that leads to the down spout near the pond is roughly 12’x18’ which, with an inch of rain is 135 gallons of water! Nashville, TN gets 4-5 inches a month through the spring, summer, and fall. We have two rain barrels (110 total gallons) set up to collect rainwater from the roof—add a float valve to the pond to automatically top it off, and we’re set!
Rainwater flows into the pond as needed, we feed the fish, they poop, which fertilizes the water that we, in turn pump out to the gardens. We rarely need additional water or fertilizer. It’s a win-win when our hobbies can overlap like this!
Happy Fish Make More Fish
It shouldn’t come as a surprise that in a well-sustained ecosystem, fish and plants are happy in garden ponds. When you’ve currated a natural environment, “life finds a way” – obvious Jurassic Park reference. Fish breed, plants propogate and eventually, I’ll have more than I can handle! That’s where AquaFindr comes in. You can sell fish online and limit distribution to local pickup, or even ship nationwide—and it all goes to help support your local aquarium club!
