Introduction: Small DIY Aquaponics System
This is a small aquaponics system i built so i could experiment with the concept. If it works out well for me I'd love to build a large version of this system but before I do want some working knowledge of how it works and any problems i might encounter before I invest a lot of time, effort, and most importantly $$$ into it. This way was a cheap and easy way to gain that knowledge as well as a fun little project. I also want to see what will grow well in the grow bed.
Step 1: Tools and Materials
First things first! Tools and materials.
2. 3/16", 1/2", 7/8" Drill Bits
4. Pipe Cutter
5. Razor Blade
7. Thread Seal Tape
1. 15 Gallon Plastic Bin (Grow Bed)
2. 1/2" Irrigation Tubing
3. 2 1/2" Ball Valves
4. 3 1/2" Barb Adapter
5. 1/2" Flex Pipe Tee Insert
6. 1/2" MNPT X Barb 90 Elbow
7. 2 #14 O-Rings
8. 2" PVC Pipe 8 3/4" long piece
9. 2" PVC Cap
10. 1 1/4" PVC Pipe 6 5/8" long piece
11. 1 1/4" PVC Cap
12. 1/2" PVC Pipe 5 5/8" long piece
13. 1/2" Male Adapter
14. 1/2" Female Adapter (Electrical Conduit)
15. 2 1/2" PVC Pipe 3" long piece
16. 2 1/2' 90 Degree Elbows
17. Growing Medium (I used a combo of hydroponic rocks and pea gravel)
18. 30 Gallon Plastic Tote (Fish Tank)
19. Black Plastic Sheeting
20. Plastic Storage Shelves
21. 100 - 130 GPH Submersible Pump
Some of the lengths here are approximate because you have to cut to fit and fine tune the system by taking a little off here and there. Also I had to use an electrical conduit fitting because normal pipe threads are tapered and you can't screw them down all the way. I needed a tight fit to prevent leaks from the grow bed.
Step 2: Building the Automatic Siphon
After doing quite a bit of research on these systems i decided to go with a flood and drain system. It seems like the easiest system to set up and maintain and once its up and running it will run itself with very little need for intervention on my part. In my long and winding travels through the various websites, PDF's , and videos out there the most reliable way to make this system work was the use of a bell siphon. This consists of a 1/2" diameter pipe (the upstand), the 1 1/4" bell (a capped PVC pipe with crenellations cut in the bottom), and a gravel guard (everything I've read says you want to maintain about a 2:1 ratio in the pipe size). The upstand is inserted into the 1/2" male adapter which passes through a hole in the bottom of the grow bed with an o-ring to prevent leaks from the grow bed. The female adapter attaches to the male adapter from the outside of the grow bed. The drainage assembly made up of the 2 90 degree elbows and 3" long PVC pipes is then inserted into the adapter.
Step 3: The Water Pumping System
The most vital part of the system is the pump. My pump is rated at 180 GPH but since I'm pumping the water up about 2 feet that falls off somewhat . Even with the lower rate it is still to much for my purposes but I put it to use. First I attached the pump to a small paver stone using zip ties to keep it pretty much where i put it in the fish tank. Then comes 1/2" diameter irrigation tubing running from the motor to a barbed tee fitting. To this I attached a small piece of irrigation tubing and a threaded adapter so I could screw on a ball valve. This allows me to divert some of the water flow from the grow bed to the tank adding aeration to the water as well as water movement. To the other barb i attached a longer section of irrigation tubing a threaded adapter a ball valve another threaded adapter more irrigation tubing and a 90 degree elbow fitting. This is for pumping the water into the grow bed. The ball valve is to control the flow of water into the grow bed which is very important for the proper functioning of the siphon.
Step 4: Testing the System
Now for the fun part, seeing your hard work in action. I put the system in its final location, remember moving 25 gallons of water plus 14 gallons of rocks equals a hernia, so you do not want to have to move this. I filled my tank with water and added a water conditioner from the aquarium store to remove the chloramine, if your local water utility uses regular chlorine you can just leave the water out for a couple of days and it will evaporate out on its own. Position your water inlet for the grow bed (mine is held in place with a zip tie) and fill it with your chosen grow medium. Now plug in your pump (be sure to read the instructions that come with your pump) and remember that water and electricity are not friends and when combined most especially not yours! The ball valve for your grow bed needs to be adjusted based on how your siphon is functioning. If the siphon doesn't stop your water flow is to high, if your siphon doesn't start your flow is to low. It takes a few cycles to get this adjusted properly. For mine it fills in 13 1/2 minutes and drains in 1 1/2 minutes. Now is your opportunity to check for leaks and change anything that needs to be before you add fish.
Step 5: Stocking Your System
Almost there! Here I've added 6 broccoli seedlings and a couple of mint cuttings I took plus about 20 small goldfish. I chose the broccoli because its a bit chilly here in Florida right now (65 - 75) and broccoli should do well at these temps. I used goldfish because they are very cheap, I paid $4 for 20, and they are pretty hard to kill. I figured since I don't know anything about fish I'd probably kill quite a few of them. To date, 2 weeks after adding the fish, I've only had one die. I was concerned because the water was quite dirty the first day but has since mostly cleared up so I wouldn't worry about that.
Step 6: Testing the Water
I test my water twice a day with a kit for aquariums I picked up at the pet store. Once in the morning, and once in the evening. You can see in the picture I also keep a log of all my results and make notes about my observations such as water quality, how the fish are doing, and anything else of note. When I first tested my water my pH was about 8.0 but has slowly drifted down to 7.6 in the last 2 weeks. There was also a small amount of ammonia present but that's normal from what I've found in my research. Nitrite and nitrate were both 0. After 2 weeks I got a sudden spike in ammonia so I've stopped feeding the fish until it reduces (that will mean i have beneficial bacteria growth. HOORAY!). Once you're up and running all there is to do is feed the fish, test your water, check to make sure everything is running, and wait till you can harvest fresh veggies.
Step 7: Lessons Learned
1. For aquaponics bigger is probably better. I doubt i could raise any useful quantity of edible fish in this system. At most maybe a couple of tilapia and that's probably pushing it.
2. Use a hydroponic grow medium like Hydroton. It's more expensive but far lighter and easier to work with, also pH neutral.
3. It helps to have an extremely tolerant girlfriend who doesn't mind that you've just built this thing in the living room of your one bedroom apartment and intend to make it a permanent fixture on the balcony (this is probably gonna cost me some flowers at the very least).
4. Do not let your girlfriend see any dead fish as this will result in yet another neccesary order of flowers.
5. Patience is a virtue that I still have not totally mastered.
Total Build Time: 1hr 30min
Daily Maintenance Time: 15min
Total System Cost: $40 (Approx. I used what I had laying around as much as possible.)