Introduction: Ebb and Flow Aquaponics for the Office
Grand Prize in the
Indoor Gardening Contest
Aquaponics is a hybrid between Hydroponics and Aquariums. In an Aquaponics system, an Aquarium stocked with fish will produce Ammonia and other waste expelled by the fish. This waste water although harmful for the fish is good eatin' for plants, so, the water is pumped out of the aquarium to outside grow beds where parched plants wait for a meal. With the help of nitrifying bacteria, the waste water is broken down into useful nitrates that the plants eat through their roots. This waste water thus goes through a filter of plants and the 'cleaned' water is re-introduced back into the aquarium.
This instructables show cases an Ebb and Flow system. Particularly this is a beginner system best suited for 'wet feet plants' i.e plants that enjoy having their roots cycled through water often, like, say, swamp and marsh plants. My personal goal was to start harvesting herbs for my favourite tea and build a space where I could zone out by watching the fish. However, I quickly learned that not all plants can be fed as frequently as others. Also, some plants are very particular about how much sunlight they get. I experimented with many different types of plants, the ones that thrived were the most alien and interesting looking! SCORE!'
This is a video I made in the early stages of the project. That chugging sound you hear, thats the sound of success...
Step 1: Need to Know:
You may want to start with setting up the Aquarium first and getting a head start on 'Cycling the tank'. Read up on the Nitrogen cycle and remember that it is delicate, takes time to start and is the back bone of an aquaponic system. By the time you finish building everything else in this instructable, your Aquarium may very well be only part way through cycling !!!!
Nitrogen Cycle: You will need to understand how the Nitrogen Cycle works, i.e how to make Nitrate out of Ammonia with the help of our good friends, nitrifying bacteria. This is key to every ecosystem (or most?), thus it applies to the fish in the tank and the plants involved.
Bell Siphons (or Siphon Valves): For this project I chose bell siphons because I wanted to fill my grow beds to the brim ensuring that all the roots of my various plants received nutrient-enriched water. However, you can't have the grow beds flooded with water at all times (otherwise you drown the plant). You should also know that once a bell siphon starts, it has a punch. When building your tank, keep in mind to aim the water exiting your bell siphon away from anything delicate.
Photosynthesis: Plants need Light and carbon dioxide (CO2) to thrive. Its easy to give the aquarium plants a lot of light, but its trickier to get CO2 to the leaves, especially when they're submerged underwater. Read up on photosynthesis, particularly photosynthesis for freshwater aquariums.
Plants General Info: Figure out what plants you wish to grow both inside and outside the aquarium. For the outside ones spec out how much water they need a day (if you can.) For the beginner I recomend plants that you'll find on river beds and swamps. For aquatic plants figure out what they best thrive in, and then figure out which fish would be happiest with those plants.
Step 2: Get the Room, Shelving, Reinforced Stand Then the Tank!
Get the room
The rule of thumb on the weight (in lbs, pounds) of a fully loaded aquarium (includes stones, gravel, equipment etc) is approximately 10 times the volume of the tank (in gallons). Ask yourself, how big will your tank will be (in gallons) and can the floor of your room actually support that weight? Worry about this if you are installing 50 gallons or larger. Also note that a smaller tank is harder to manage (in terms of biodiversity) than a larger one. A larger tank is more expensive than a smaller tank. I settled with 30 gallons because it fit perfectly in the shelving from Ikea I built up. I don't recommend anything less than 20 gallons.
Shelving is critical for this project. The tank I got is exactly 29.5" long, by 16" tall by, 12.5" wide. The stand designed to support the tank is exactly 31.5" long, the Ikea shelving has a max inside space of 32" long [that was a fluke:)]... Build your shelves around your aquarium making sure there is at least 12 inches from the underside of the first shelf to the top of the aquarium tank. Make sure you have at least 2 shelves with 30 inches between each. The top shelf doesn't need a whole lot of clearance to the ceiling.
Note: Make sure that the the shelves are sealed and that they won't suck up water!!!
Get a stand that can support the weight of your tank and then some. There is a lot of material on the internet on how to support aquariums properly which I own't discuss here. The point to understand is that hundreds of pounds of weight is going to cause EVERYTHING TO BEND, whether you see it or not. This bending is going to add stress to the aquarium. If its not protecting against enough of the bending, your glass or seals will break and you'll have a royal mess to clean up!.
Tank and position
Once you have the shelves, get yourself a tank sized to the shelves.
Snug everything up in a room of your choosing. Just know that if the tank is in direct sunlight, you will probably get blooms of algae growth. This could be a good or bad thing depending on what fish you have or how you want the aquarium to look.
Step 3: Water Manifold
Basic water manifold
Your top shelf will hold the water manifold. This is where water will be pumped into and then flooded out to the various grow beds / return to tank. This is really as basic as it gets, all your grow beds will get some amount of water at the same time with no automated controls. I'm sure you can automate it easily.
- Get a plastic bin that will clear the distance between your ceiling and top shelf. Measure and trace the bin within the centre of the top shelf.
- Using hole cutters, drill in the appropriate sizes for your through hills into the plastic bin.
- Deburr the plastic shelf and polish with a fine sand paper if need be.
- Re-centre the bin on the top shelf and trace in those holes you just cut out. Cut out the holes in the top shelf.
- Screw in the bulk heads into the water manifold to the top shelf. Most bulk heads come with a rubber gasket, but I find them leaky. A good bead of 100% silicone as you install the through hills does a makes a very good seal.
Lower Shelves (For Grow Beds): This is very similar to the water manifold.
- Trace your bins onto your lower shelves, you may want to consider where your bulk heads are going to be relative to the grow beds below, or to where they will re-enter the fish tank. Just know that fish don't appreciate water crashing down onto their heads at random locations.
- Using the hole cutters drill in holes for your through hills. Trace those holes into the Lower Shelves and cut the holes again.
- Screw in the bulk heads into the grow beds on the lower shelves. Most bulk heads come with a rubber gasket, but I find them leaky. A good bead of 100% silicone as you install the through hills does a makes a very good seal.
Step 4: Stand Pipe for Bell Siphon
Hopefully you read up on Bell Siphons!
Note: DO NOT USE CLEAR HOSING, THEY ARE ONLY CLEAR IN THIS INSTRUCTABLE TO SHOW YOU WHAT'S HAPPENING INSIDE.
You are going to want to make the tops of your stand pipes act like funnels. You can do this any number of ways, (literally hot glue in a plastic funnel?) here's how I did mine:
- Get a PVC from reducer from 1" to 1/2".
- Sand in a conical / spherical funnel. (I used the strange cone/sphere sanding bits in an old router kit... only I attached it to my power drill!)
- Install reducer onto 1/2" hose barb (or nipple as some people call it)
- Determine the height of your stand pipe. A quick way is to install the hose onto the barb, seat the hose into the through hill (which is already installed in you grow bed) eye ball an appropriate height, pull out the hose and trim to the desired length.
- Drill out two 1/16 holes where the house meets the top of the through hill. (This is useful when water needs to slowly drain back into the fish tank.. i.e when theres a power failure.)
Repeat for every grow bed you have.
Step 5: Bell and Snorkel for Bell Siphon
Note: DO NOT USE A CLEAR BELL, THEY ARE ONLY CLEAR IN THIS INSTRUCTABLE TO SHOW YOU WHAT'S HAPPENING INSIDE.
- Measure out the height of your stand pipe plus 1/2" against a water bottle (REFERENCE FROM THE BOTTOM). Cut off the top part of the water bottle from the measurement you just did.
- Cut in many fine slits along the open portion of the bell.
- Select a drill bit with diameter roughly the same as a bendy straw.
- Drill in a hole at near the top of the bell. The hole should be between the top of the bell and above the standpipe.
- Cut a bendy straw to appropriate lengths and hot glue into the bell.
- Cut off the top part of another 500ml water bottle ensuring the the tube you just cut out is taller than your bell by at least an inch.
- Cut in many slits at one of the open ends of the tube
- Cut in one slit perpendicular to an open side that is roughly the width of a bendy straw. The slit should be long enough so that the bottom of the slit roughly lines up with where the hole in the bell is once everything is glued into the grow bed.
- Cut in notches along one water bottle cap.
- Drill in a hole at the top of the same water bottle cap.
- Glue the open side of the cap you just modified to the open side of a new water bottle cap.
Floating Switch Tube:
- Cut off the top part of another 500ml water bottle ensuring the the tube you just cut out is taller than your bell at least by an inch.
- Cut in many slits at one of the open ends of the tube
Set up grow bed:
- Roughly trace where your Bell and Snorkel tube will be in the grow bed.
- Remove the items and apply hot glue to those areas.
- Quickly install the bell and Snorkel tube ensuring that the bendy straw is in position.
- Once the hot glue is cured, gently pull out the bendy straw and cut ouff a few millimeters from the bottom of the straw.
- slip on the snorkel cap.
- Finess the cap+bendy straw back into the snorkel tube.
Ok, what and why did I just do this???
The Snorkel Cap will be used to help break the siphon as the water level drops below a certain point in the grow bed. The snorkel cap works off of buoyancy. As water fills the grow bed the cap will float but will be held at a particular height by the bendy straw. The cap will eventually fill with water as the water level rises. When the siphon starts and water level drops the siphon inside the bendy straw will suck water out from the snorkel cap as well. When the water level drops to where the cap is, all the water will be sucked out of the cap without any new water filling the cap up. When all the water is sucked out, the siphon will suck in air only and this will break the siphon. Remember, that the bottom of the bendy straw will determine the lowest water level of your grow bed during the siphon.
Step 6: Sump Pump and Air Pump
A new aquarium will need the mechanical aid of filters to help kick off the nitrogen cycle. A water fall filter will help disturb the surface of the water (to allow CO2 out and push O2 in) but isn't great at helping the nitrifying bacteria do its thing. Submersible sponge filters are better at collecting Ammonia and bacteria on the sponges and getting the nitrogen cycle started but take a lot of space. Choose one, or the other, or both depending on what you've created. You will also need a submersible sump pump (which is also a mechanical filter in its own right).
Your sump pump will have to be able to drive water to your water dispenser from step 3. Make sure that the pump is capable of driving water to a height of 6'.
Glue the submersible sump pump to a flat stone using 100% silicone. This will help keep it in place as you start to install Rubber hoses and the works. This is optional for the submersible filter as well.
Connect your pumps and filters to lengths of hose (note, lengths are based on your set up, you may want to spec this out before you get started).
If you are using an airstone or an air driven submersible filter, connect them to the air pump with long length of hose. You may want to put your air pump on a spongy pad to dampen their sounds. Depending on the model you get they can be loud.
If you bought a CO2 system install it now. Otherwise, skip to the DIY CO2 generator in the following DIY Link __
Step 7: Aqua Scaping!
- Mechanical: Place your pumps and filters where you think they will be least noticeable. Later bury the sump pump with large and medium sized stones. *NOTE: You may want to install an Air Stone at this time - and/or, your submersible filter needs an air line.This will be the time to connect these items with long lengths of hose (sized to the filters)
- Drift wood: A must in my opinion. Not only does it look great but a lot of fish species need driftwood to thrive. I recommend going on a hike and picking up some drift wood then spending countless hours shaping it to what you want (art!) and bathing it in boiling water+vinegar. Something called Tannin will start to seep out (like tea steeping in a cup) while you boil / bathe it. Rinse it out and get rid of the tannin before introducing the drift wood back into the aquarium. (tannin will gradually seep into the aquarium, this isn't a problem.) You can also use Driftwood to simulate caves. If you have a massive piece of driftwood that you wish to bury partially, then install the driftwood first. You may need something to keep it down like glueing it to stones with 100% silicone, or, use the shelf just above the aquarium surface to hold down the driftwood.
- Substrate: What style, color are you going for? Compare that to the natural requirements of the fish and plants you'll be introducing. This can range from a fine sand to aquarium safe gravel to river stone and pebbles. Don't use glass marbles as I have learned they don't work great as a substrate for the nitrogen cycle. Install the Substrate by pouring it over your drift wood and everywhere else in the tank. Get imaginative with it too.
- River Stones: River stones work well in covering up equipment in the aquarium. I chose rocks with Quartz and put in a pile of broken black stones that i found in my alley. The sparkling effect of quartz (or Obsidian glass) really adds to the aquarium, don't underestimate it! Boil any stones in vinegar before you put them into the aquarium. If they start to fiz, that means they have Calcium Carbonate, I suggest to get rid of these stones unless your fish and plants thrive in rich calcium waters.
- Aquarium Plants: I chose hearty species that could deal with high amounts of ammonia. Anubias, Crinum and Crypt plants make up 90% of what's in my tank. Other species of plants didn't do so well as the tank cycled up, and they sorta just melted. Consider tying plants to the drift wood with thread.
- Water: De-chlorinate any water going into the Aquarium by either introducing de-chlorinating chemicals, or to let the water standin the sunshine for 24 hours. You'll get rid of chlorine this way, but not chloromine. It is in my opinion that hearty fish can handle chloromine but not chlorine as much. If possible get some Aquarium water from the fish store to help kick off the nitrogen cycle. Or... pee in your water and mix it up. Worked for me. Pour in the water gently so you don't carve into the substrate. Consider pouring the water in along the glass.
- Note: Anything thats going in the aquarium, other than the plants should be cleaned thoroughly. I recommend to boil in a 50/50 or 25/75 mix of water to white vinegar for a few hours and leave overnight. Rinse thoroughly before putting it into the tank. This particularly applies if you have found something in the wild you would like to use. If you see rocks or sand that are 'fizzing' get rid of them, that means that calcium carbonate is present and it is reacting with the Vinegar. You don't want Calcium Carbonate in your aquarium (unless your fish and plants are into that sort of thing)
Step 8: Grow Media and Plants
Grow Media: LECA or expanded glass media (in the photo), anything that is pH neutral and good for "hydroponics" will work for Aquaponics. The higher the porosity of the grow media, the better your plants will thrive.
Plants: I recommend plants that are 'wet feet' and enjoy moist environments, like swamp plants and river bed plants. Compare the two photos. Mint and herbs vs Elephant ears and others. The elephant ears exploded in growth as compared to the mint, which eventually rotted away and died. The mint drowned (slowly) because the water from the aquarium was being cycled through the grow bed a few times a day. The elephant ear on the other hand loved and I had to trim it back multiple times every month.
Dump in your grow media into your grow beds. Make a mental note to keep the really small bit of grow media as far away from the Bell Siphon as possible. Make sure that the level is about an inch below your Snorkel Tube or Floating Switch Tube. Installing plants into the grow media is a pain in the butt... there is no real easy way of doing this. Just, try to scoop aside a bunch of grow media and push in the plant without damaging the roots too much.
Step 9: Plumbing and Dialling in the Bell Siphons
- Run lengths of your vinyl rubber hosing from your Through Hills to the area of the tank where all your aquarium rocks are piled. Don't arbitrarily aim these hoses anywhere at the tank as water jetting in at different locations is very stressful on the fish.
- Run lengths of hose from your top shelf water dispenser to the grow beds
- Attach a ball valve at the end of the hoses from the water dispenser to the grow beds to control flow rates.
Step 10: Add Fish After Nitrogen Cycle
The only good way to know if the nitrogen cycle is complete is if algae is blooming. Other than that introduce hearty fish. When they start acting very cheerful introduce more fish. Dont over stalk your tank. If you do, add more plants!
Zebra fish and Dwarf Rainbows are very hearty and are great to get the tank up and running. When the conditions are just right try adding more.
When you are ready for more, try the 1-gallon-per-inch-of-fish rule. Depending on how well your aquaponic system is doing you can try to over stock the tank by going above this rule.
Step 11: Lights (optional)
DIY lights are the way to go. Buy a reel of them and and cut them in lengths to run the underside of your shelves. Solder all the connections properly, and use epoxy to hold the lights to the back of the shelf.
Step 12: Timer Vs Arduino
For a beginner system, just use a regular timer from the hardware store to turn the sump pump on and off.
For an advanced system you can use an arduino to turn on the sump pump and control which grow beds get water by turning on solenoid valves. In my system I used a photo resistor to see if the sun was up or down and turn on the system appropriately. I also used solenoid valves to feed certain plants less than others. (
I'm sorry about the lack of instructions in this step!)
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Please be positive and constructive.