I was jealous of my neighbors “water feature” and wanted one. I couldn’t justify the cost of putting one in and it not be productive. Then while cleaning out my MIL junk barn, we found a small plastic pond. I dug a hole, and with a spare pump from my greenhouse aquaponics I had a water feature. No extra cost. But how to make it productive? Fast forward a year. I decided I wanted a bigger pond and stock with fish. So again I dug the hole by hand. It kept getting bigger and bigger as I thought of all the things I could add.
Here is a picture of the hole. it is 4 1/2 feed at the deepest 15 feet long and 8 feet wide.
Next we added a roofing liner. I chose EDPM, 60 mil thick. I got a change through my professional work history to meet an engineer who works at firestone. Who make both roofing liners and pond liners. The material is identical. The only difference is the anti caking agent they use when rolling it or folding it. But here’s the catch, the pond liner is quite a bit more expensive. I just bought the roofing liner, and washed it several times, then with soap, and rinsed a few more. I cycled my system for several weeks before adding fish or plants.
Here are some photos of the system when we just got started.
Here is the same angle today.
The overflow from my rain catchment system goes into the pond. After a few spots in the yard heal from chicken devastation, I will swale and fence in the area to remove the pipe. It is only there to keep the water from eroding the surface soil.
The overflow of the pond goes into my garden.
When stocking with fish I use pet store feeder fish. Here locally I can get 100 different colored and patterned goldfish for $12.79. They are pretty hardy to get the system started, and add some color. The fish I started 18 months ago were around 1” and now are 9”+ and 1-2 lbs each. I feed duckweed and a handful or organic fish pellets. Duckweed will duplicate every 24 hrs in summer, and has more protein than soy and the feed I give them. I bought my first duckweed from a pond store, and it just keeps going. I have given duckweed to people on tours when asked and now sell if anyone wanted to start their own for their systems.
For the production piece. I added drip irrigation to recycled plastic containers which I hung from my deck railing. I took 2L bottles and cut off the bottom. Then drilled holes in the lids. The top bottle drills to the second, and then to the third, which drains back into the pond. In each bottle I used coconut coir as media. We planted cucumber, 3 kinds of melons, 5 varieties of lettuce, strawberries, peppers, and cilantro. The liner is pulled up so high to catch the drip irrigation and to keep chickens and the dog from the back side of the pond.
For the biofilter I again built my own. Recycled plastic feed containers, and PVC pipe. Inside there are river rock, lava rock, pea gravel and more coconut coir. The top container flows to the second which has a diverter and the drip irrigation. Again all recycled parts. Most of the plants I started from seed. The only things that cost me anything were the pump, bought off season for 75% off, and the liner. Since I bought roofing liner, rather than pond liner it saved me a few hundred dollars. The fish, but now we restock it ourselves when we go fishing. Any minnows that don’t get used, or fish that are too small to eat go to the pond to grow, and keep down mosquito population. The rocks were picked up from fields that get plowed. the 55 gallon drum serves no purpose than giving additional height. I am working on another system of hanging baskets from the pergola to give more growing area.
Here are some additional photos and description of our outdoor aquaponic system. I have experimented with different growing systems. From drip irrigation to floating rafts.
Q: What do you do in winter? All the plants and the drip irrigation go away, mainly to compost. I disconnect the biofilter, and run a fountain to keep the water from freezing and oxygenate the water. The water plants move to the greenhouse, and a stash of duckweed goes into the greenhouse, and in the indoor system, to be returned next spring.
Q: What kind of fish can you use? Any kind of fish that will be winter hardy. You can use koi, goldfish, catfish, bluegill, carp, sunfish etc. You may be able to use tilapia but the water needs to maintain 50 or above and for optimal conditions 70-80 degree water is needed. This year we didn’t get the system cycled in time to optimize the growing season for tilapia. Next year we may put them in once the water maintains above 50 overnight, and then harvest before the water drops below 50. MAYBE 9 moths or less. for now bluegill, sunfish, and catfish are stocked along with goldfish for color.