Introduction to Aquaponics




Introduction: Introduction to Aquaponics

When I first heard about aquaponics, I was pretty stoked. It was a foreign concept at the time, being able to grow fish and plants in harmony. It's taken a few years, but I finally built a system that meets my needs. It was also a ton of fun to build. The experience of seeing green plants and hearing the gurgling of water as I walk down into my basement is very rewarding and unlike anything else I've built. This system is simple, relatively cheap, and a great introduction to aquaponic growing.

To begin with the basic concepts of aquaponics, the basic principle is a water-based system in which fish waste provides nutrition for plants, and plants filter and oxygenate the water in turn. Bacteria are an integral component, as they are responsible for the breakdown of fish waste into nutrients plants can absorb. Aquaponics is naturally organic, water efficient, space efficient, and produces prolific amounts of plant growth. The fish can also be raised and consumed in a large enough system. Aquaponics is a great option for anyone wanting to try an different angle at indoor gardening, as it has a certain 'life' factor missing from traditional indoor gardening. Space efficiency is usually a concern with growing indoors, and aquaponics is able to be scaled up or down to almost any scenario. Aquaponics is one of the most productive growing methods known to man, and nothing screams efficiency quite like watching aquaponically grown plants spring up twice as fast as traditional planting.

Please note that almost all pictures have notes attached that you'll need to click on the picture to see.

Next let's talk about some of the main aquaponics growing methods.

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Step 1: Aquaponic Growing Basics

Plants are the main event of the aquaponics show. They have the capacity to produce far more food than the fish will. They will happily grow in an aquaponics system, but there are a few different methods of growing. Here is some theory on how plants are grown aquaponically.

Aquaponic growing of plants is typically conducted in three main ways:

-Media filled grow beds are the simplest and most common method of growing plants. A grow bed can be any apparatus capable of containing the grow media (gravel, expanded clay, river stones- more on this later) and water. The plants are grown in the media similarly to how they would be grown in soil. This is what I used for my system.

-Deep water culture is a system in which the plant roots are submerged in water. The plants are typically suspended with a foam sheet at the top of the water. This is a little bit trickier to implement, as the natural filter of the grow media is not present.

-The last main growing technique is the nutrient film technique (NFT). This technique typically involves the plant roots being laid in a 'gutter', where a thin stream of water is passed through the roots. This can be a very productive method of growing, but can be complicated to physically set up.

Next, let's check out some of the different setups in which these concepts can be implemented.

Step 2: System Design

There are quite a few aquaponics system designs out there. The basic requirement for the system is to flood and drain the grow bed (plants need nutrition, but cannot be in water constantly) and to keep the level in the fish tank constant while cycling the water. I'll outline the design used in this project.

The simplest possible design is simply having a grow bed above a fish tank, then pumping water out of the fish tank into the grow bed on set intervals. The water will then drain back into the fish tank. The main issue with this system lies with the water level in the fish tank fluctuating. If the grow bed is properly sized, it will have at least as much volume as the fish tank. Therefore, the water in fish tank will be nearly all pumped into the grow bed once the pump cycle starts. In the interest of the fish, this is not desirable. The fish will be stressed as-is, considering a freshly started aquaponics system isn't exactly an ideal, stable environment.

The solution to this issue is a design known as CHOP (Constant Height One Pump). This system adds a third tank to provide the water to fill the grow bed instead of drawing from the fish tank. Therefore, the fish tank is kept at a constant height (CH) and one pump is used (OP).

I used a CHOP system, using three identical containers stacked on top of each other. The grow bed is on top, fish tank in the middle, and sump tank on the bottom. There is a drain on the bottom of the grow bed, so it will completely drain before the next pumping cycle. This is necessary so the plants can breathe and not be constantly submerged. The grow bed also has a drain placed within an couple inches of the top so there is no risk of overflow. The grow bed drains into the fish tank, which I will go into detail with later. The fish tank is kept at a constant height by a drain also placed within a couple inches of the top. The fish tank drains to the sump tank, where the pump is located. Water is pumped from the sump tank to the grow bed.

This is just an overview, I'll be going into more detail as each of these parts are built. A diagram of this system is included, check it out!

It's decision time! Considerations and options will be outlined next.

Step 3: Decisions and Considerations

Some considerations and choices that need to be addressed when designing your system:

The first consideration to think about is how large of a setup you would like to build. The main decision that needs to be made when designing your system is whether or not to eat your fish. In order to raise fish to an edible size, you will need a decent sized system. A rule of thumb is to stock one pound of fish for every five to ten gallons of fish tank. For example, a one foot long tilapia weighs around a pound and a half. A tilapia takes about nine months to reach this edible size. As stated below, in the system I designed (with identical components) a maximum of three mature tilapia could be held at once. More fish could be raised if growth was staggered (fish would have to be separated or they would eat each other), but in a best case scenario a fish could be harvested every two to three months. The fish would also have lived their lives in a crowded tank, causing a poorer quality of life and increasing chances for issues to arise.

The other main decision that needs to be made is the basic design of the system, as was discussed in the previous step. It is recommended by most experienced growers (and myself) to follow the design I've used and laid out in the previous step, a CHOP system with a media filled grow bed. If you choose to give another design or grow method a shot, I'd love to hear about it too!

For my needs, a relatively small system was decided on. I was not looking to produce any significant amount of my food, just some herbs and vegetables. Therefore I chose a fairly small system that would fit well in my basement. I decided on not raising fish for consumption (though I could have), as I didn't want to make my system quite so large and invoke more complication. My system ended up having roughly 17 gallons of fish tank, so raising fish for food was a possibility. However, I would only be able to raise a few fish to maturity at a time, and would end up eating one every several months. This was not worth it to me, and I therefore used goldfish in the system.

Next let's check out the physical components to build this for real.

Step 4: Build Plans

Here are the materials and "big" parts I used to build this system, and some considerations for the build I wish I would have thought about more during the planning stage.

After the system size and design has been determined, some kind of support has to be used. I used a sturdy table I made a few years ago and some scrap wood. A metal shelving unit would be an better option. Whatever you choose, keep in mind it will need to support a few hundred pounds minimum. In my case, containing about 34 gallons of water at 8 pounds a gallon comes to somewhere around 270 pounds in water alone (when the grow bed is filled and the water is not in the sump tank sitting on the floor). Add in gravel, plumbing, and other goodies and you have something that could easily cause a weak support system to fail. Find a shelving system that meets your needs and go with it. Since initial construction, I have placed some 2X4s under the scrap wood grow bed platform for extra support, as the platform was starting to sag. Keep in mind that you will either need to plumb the pipes outside the shelving footprint, or cut holes in the platforms of your shelving for the pipes.

The simplest way that I've discovered of gathering and sizing a grow bed, fish tank, and sump tank is to buy three identical plastic bins. There are all sorts of creative designs (often out of repurposed materials) people have made to serve these purposes. Here, I'm sacrificing creativity and eco-friendliness for simplicity and efficiency. The plastic bins can still be recycled or reused when (if) you're done with the aquaponics system. I bought three 70 quart storage bins at walmart for $7 apiece.

The next parts you'll need are the plumbing pieces. I used 3/4" PVC and found it to be an appropriate size for my system. PVC is cheap, so get extra. Get at least two 10' lengths (I used about 1.5). Grab some tees, elbows, and end caps. I used two, four, and two respectively. Like I said, these fittings are cheap so buy extras in case one gets misplaced or new design features are added.

You'll also need some tubing (5/8 clear vinyl works great with the selected pump).

Other materials I found useful to have on hand was some 2X4, zip ties (lots), and a healthy amount of patience.

Step 5: Other Things Needed

We've addressed the main structure of the system by now. However, there is far more necessary to create a working aquaponics system. Let's take a look.

Pump: The pump is an integral part of the system. Without it, there is no water circulation and the plants and fish die. This is not an area to scrimp on. When choosing a pump, be sure that it is able to fully fill the grow bed (at least!) during the 15 minute period it is turned on. Pumps are rated by their flow rate, or how much water can be pumped in an hour. Keep in mind that this rating is taken with zero head, meaning the pump doesn't need to elevate any of the water. There will usually be a graph on the pump box or website showing the flow rate as head increases. In our system, the pump will be operating with at least a few feet of head, creating resistance for the pump and reducing the flow rate.

This is the pump I used:

Not terribly expensive, but plenty of pump for this size system with a solid base of reviews. It has worked great so far.

Timer: Another key part of the system, this is how the flood and drain cycles are controlled. There are other ways of controlling this, such as a bell siphon, but a timer is the easiest option to set up. The timer will need to have 15 minute on/off intervals, so we can turn the pump on for 15 minutes and let the grow bed drain for 45.

I used this one:

I also used a cheap christmas light timer I had laying around for the grow light. Not needed, but I figured I may as well use it.

Grow Light: In my case, the system is located in my basement where minimal natural light gets in. If you have the luxury of setting your system up in a place it can receive natural light, great! If not, you'll need a grow light. I bought a socket and shroud from the hardware store.

This is the grow light bulb I ordered:

Expensive, but with many positive reviews and I had experience with it previously. One of the ways I would cut costs if going for a super low budget system.

Silicone or Bulkhead Fittings: These will provide a seal for your pipe-to-storage bin connections. Silicone is the cheaper option by far, and is what I went with. It works fine, but in retrospect I should have gone with the more professional choice of a bulkhead fitting for at least the grow bed drain.

Picked up a tube of silicone for $4 at the hardware store.

Grow Media- Discussed in step ten.

Step 6: Let's Go!

The first thing you'll need to do is make sure the bins fit in your selected shelving with room above the fish and sump tanks for plumbing. Next we'll prep the bins for overflow drains.

For the fish tank, drill a hole for the overflow pipe an inch or two below the top of the bin. I drilled as close to to the top as I could, which was limited by the handle on the bin. The drains ended up being about 2.5 inches below the top of the bin. I would recommend drilling the grow bed drain lower if you plan on using a floating grow media (more on grow media later). This will reduce the grow media spilling over the top of the bin. 3/4" PVC is slightly larger than one inch in its outside diameter, so a 1" spade bit and some sandpaper should be the easiest way to get a snug fit around the pipe.

After this is done, you'll need a hole in the bottom of the grow bed for the drain. Same drilling procedure as before, just try to get as close to the center of the bin as you can.

Next, set the bins up on your shelving. You'll need to drill or cut an opening for the grow bed drain in the shelf/platform. Another decision that needs to be made is whether to hang the pipes off the side of the shelving or cut openings in the shelves for the shorter pipe runs (I did this).

Once you have your system laid out and vessels prepped, onto the plumbing!

Step 7: Plumbing

The plumbing is pretty straightforward for this build. As always, cut longer than you need and trim pipes to fit.

The first (and largest) plumbing assembly I created was the grow bed drain and overflow assembly. A short section of pipe will need to go from the grow bed drain hole to the middle inlet of the tee fitting. Make sure enough of the pipe sticks out into the grow bed, as we don't want to drain it completely. Put one of the end caps on the side of this pipe that sticks into the grow bed. We will be making this into a screen later. The tee fitting should be hanging over this fish tank at this point. The best setup will have the tee fitting as far away from the water's surface as possible for the most surface disruption once the drain water is spilling into the fish tank.

To set up the grow bed overflow, cut another short section of pipe to be set through the hole drilled previously. Connect this to a 90 degree elbow, then run a long pipe down to the level of your tee fitting. Another elbow and run pipe, and connect to an open side of the tee fitting. Almost done with this one!

The remaining opening of the tee fitting will be used for an aeration bar (Just a section of pipe with holes in it to disturb the water's surface and provide more oxygen). Set aside a cap and a piece of pipe between 6" and 12". We will prep this part in the next section. This is not absolutely necessary, but if used multiple streams of water will be flowing into the fish tank at once, increasing oxygen levels in the water and making the fish happier. The reason I opted to run the grow bed overflow into the aeration bar was to create more pressure for the spray bar, and consequently force more oxygen into the water. If you do not want to do this, feel free to let both pipes drain into the fish tank without connecting them.

The only remaining part of the plumbing to be constructed is the overflow from the fish tank. Same setup as the grow bed, except we will be running the end of the pipe over the sump tank rather than connecting an aeration bar.

By now all the plumbing should be cut to size and dry fit together. Let's finish it off.

Step 8: Finishing Touches for Plumbing

Almost done here. All that's left to do is drill the aeration bar, create screens, and seal everything up.

To finish the aeration bar, pop holes in a line every inch or two in your chunk of pipe. I used a 1/4" brad point bit. The sharp point bites into the plastic, eliminating the bit walking or making a divot to start the hole.

For the screen on the grow bed drain, I drilled many small holes in a PVC end cap. This may take some trial and error to get the right number of holes. The drain should flow enough water to completely drain in the 45 minute drain cycle, but not so much that the bed never fills completely. Initially, I drilled a conservative amount of holes, and later needed to drill more. Check out the pictures for an idea of how many were necessary. This would have been better to test beforehand rather than pulling the screen off to make changes in the fully set up system.

Making a screen out of an end cap is, admittedly, not the most effective approach. Debris from the grow media and other gunk clogged the small holes easily, and now I usually scrape the top of the screen free with a long screwdriver on a daily basis. Not a huge deal, as it takes an extra ten seconds when I feed the fish, but annoying nonetheless. If anyone can think of a better solution, I'd love to hear it!

If you will be using a floating grow media, a screen will also be in order for the grow bed overflow. I ended up using some non-slip drawer liner I had laying around for maximum flow. More on this in the troubleshooting section.

In terms of sealing up the system, the only agenda items are sealing the pipes where they are pushed through the side of the bins. The pipe joints themselves do not need to be glued with PVC glue. PVC force fits together rather tightly, forming a leak-free connection in this case with the minimal pressure present. As briefly mentioned before, I used plain old silicone to seal the connections. I would recommend using a bulkhead fitting for at the grow bed drain at the very least. A bulkhead fitting is a purpose built fitting that screws together from both sides and forms a complete seal. If you decide to go the silicone route, be sure to clean the surface well before applying and apply liberally.

After everything is dry and fit together, the pump needs to be set up.

Step 9: Pump Setup

The pump will be placed in the sump tank. The pump I used came with suction cups on the bottom that work just fine. Size and cut a piece of tubing. The barbed fitting that came with the pump was sized for the 5/8" tubing I had in my garage (got lucky there!), but it would be wise to make sure your tubing and pump fittings will work together beforehand. More holes may need to be drilled in your shelves if you're looking for the shortest run of tubing possible (And the cleanest look). Once the tubing has reached the grow bed, be sure to secure it as well as possible. It would be awful to wake up in the morning to find the pump has sprayed water all over the floor because the tube was not secured well enough to keep the water where it should be.

The pump's power cord will need to be secured to the lowest point possible so any water rolling down the cord will drip off at that pint and not make it to the point where the pump is plugged in.

After everything is hooked up, set the timer to 15 minutes on and 45 minutes off. The system should be ready for testing at this point. Leaks are easier to fix now than later.

Step 10: Grow Media

Grow media is the aquaponic equivalent to soil. There are a few options for grow media, mainly affecting price and ease of use. The only requirements for the grow media is to be inert (chemically and pH- no limestone), large enough to be stable and allow air to reach the planet roots (no sand or dirt), and preferably easy to work with (use lava rock at your own risk).

The cheapest and readily available option is some form of gravel fitting the requirements. This can usually be found locally for cheap. However, gravel is heavy and can have sharp edges. The media I went with is expanded clay, which is light (floats- more on this in troubleshooting) and very easy to work with. It also has a "cool" factor gravel lacks. Expanded clay (or shale) is somewhat limited by its cost. In a smaller system, expanded clay is a good option, but for anything bigger the expense can quickly shoot through the roof.

Two 40 liter bags of expanded clay were needed to fill the grow bed I used. I probably should have opted to use gravel instead, as the clay had a total cost of around $60.

Step 11: Fish

My advice regarding fish is straightforward: make sure your water is clean, then get the toughest fish you can find. An aquaponics system is prone to temperature swings, chemical imbalances, and all sorts of other things that are known to stress fish. However, without chemical free water that is within an normal pH range, your fish will never thrive (or survive day one).

In my case, I knew the water I have access to (well water) is chemical free, with a higher than neutral pH. I have no interest in testing the water and amending it to achieve perfect properties, so hardy fish will have to make do. Goldfish are one of the best options in a system designed to not raise fish for eating because they are cheap, hardy, and readily available. I used goldfish in my system and 3 out of an original 4 have survived and are doing quite well. I'm currently feeding them goldfish flakes, with plans to feed the cheaper pond fish food once they get big enough to eat it.

Options for food fish range from tilapia and South American pacu to whatever can be caught in the nearest pond. I won't go into detail on varieties of fish, as I'm not very knowledgeable and a quick google search will reveal far more than I can. Take note of the oxygen, temperature, and food requirements of prospective species.

Clean water free of chemicals is necessary. If you have a municipal water supply that adds chlorine to your water, let the water sit out for a few days before adding it to your system. It would be a good idea to let the system run without fish or plants for a few days after the plumbing and pump have been set up in this case. The chlorine will evaporate into the air after this period, rendering it safe for use. It would also be a good idea to test your water (many pet/aquarium stores will do this for free) so you have an idea of the properties.

I'd say to go ahead and fancy up the fish tank. Some gravel on the bottom will make their environment look more natural, and some 3" PVC fittings will give the fish cover and stimulation.

Another cool addition to this system is growing your own fish food! There is a swamp plant called duckweed that will grow quite well in your sump tank. Once it has established itself (a week or two), throw a pinch in the fish tank once in a while. The fish will appreciate a new food, and you will (maybe) appreciate saving a few cents a day on fish food. The duckweed will also filter and oxygenate your water to some extent, a good thing if there is a lapse in plantings.


Step 12: Plants

A wide variety of plants can be grown aquaponically. The only plants that can't are ones that won't fit (trees) and plants that have requirements different than the fish and bacteria (blueberries require a low pH level).

For starters, I've grown some kale. Later, other vegetables will be added. I chose the kale because they are cheap enough to be disposable, and there is a good chance not all the plants will make it during the initial phases.

As for how to actually grow the plants, they can be planted directly in the grow media as if being planted in soil. Live plants can be planted like this, as well as seeds. Seeds may not have ideal growing conditions in the grow media, and to fix this they can be started a number of different ways before being placed in the grow media.

Step 13: Grow Light

A grow light will be necessary if you won't be able to expose the system to natural light. Even so, a grow light will help the plants grow better in just about any condition.

Not much to say here, just attach your selected socket to something overhead (the ones sold at hardware stores for work duty usually have a handy clamp for this), screw in the bulb, and plug it in!

A simple light timer will simplify things a tad.

Step 14: Starting the System

Once water, media, and plants have been added, the system can be "cycled". This refers to establishing the bacteria that convert fish waste into usable plant food. The bacteria start growing when ammonia is present in the system, either through fish waste or another source. There are two main options-

Put the fish in with everything else on day one and hope for the best. This is the route I took. The fish toughed through the temporarily high ammonia levels well for the most part (RIP weakest goldfish).

The safer option is to introduce ammonia into the system without the fish. Ammonia is added from a different source (bottle from the store- good choice, something rotting- don't do this, urine- slightly better but I'd refrain), and the fish are spared the stress.

Once again, I would advise anyone building their own system to consult the excellent book Aquaponic Gardening: A Step-By-Step Guide to Raising Vegetables and Fish Together by Sylvia Bernstein for more information.

Step 15: Troubleshooting

Nothing is perfect the first time around! (Especially something I've built!) Here are some issues I encountered the first time around that I solved to some degree:

Grow media shifting around and burying plants- This sounds slightly ridiculous, but it was and is the most damaging issue to my system. In short, I decided to only order one bag of the comically expensive clay grow media and buy more if necessary. The grow bed was about half filled, and the floating grow media would rise and fall with the water level. This would not be an issue, but the media in the center of the bin had less resistance than the media in contact with the walls and consequently would rise and fall faster. This caused the freshly planted kale and salad greens to be moved into the floating mass of clay and pinned underwater until I fished them out.

Solution- I have ordered another bag of grow media to fill in the grow bed for less movement. For the time being, a plastic pot (with the plants in it) has been attached to the side of the bin under the tube from the pump. This way the plants can be somewhat healthy in the interim.

Pump not flowing enough water- I discovered a kink in the pump hose a couple of weeks after starting the system. This was easily fixed, but impeded the flow rate by a great deal while present and the grow bed was not completely filled.

Solution- Unkinked the hose, keeping an eye on it.

Grow media getting stuck in grow bed overflow pipe- The grow media would float up and jam up the pipe. I did not want to make another pipe cap screen as the overflow pipe needs to flow as much water as needed, and the small holes in the pipe cap provide too much resistance to flow.

Solution- I grabbed a little piece of non-slip drawer liner (essentially a sheet of vinyl consisting of half holes and half vinyl) and zip tied it over the pipe. Crude, but working great so far. I'm open to suggestions on this.

Step 16: Costs and Analysis

Here is the list of everything I used in this build with prices included. I'll also look at how this could have been built for cheaper.

  • Table/Shelving unit- Free to me, comparable shelving unit $50
  • Plastic bins- $7 each, $21 total
  • Plumbing- $10
  • Silicone- $4
  • Pump- $26
  • 15 minute timer- $12
  • Grow media- 2 bags, $58 total
  • Grow light assembly- $37
  • Fish and fish food (including duckweed)- $30
  • Tubing- around $2 if not on hand
  • Plants- $10

Total- $210

This was (of course) more than I expected this project to cost. Costs could be reduced by:

  • Buying gravel instead of manufactured grow media. This would cut costs by roughly $50.
  • Not buying a grow light, or buying a cheaper one and using an existing socket. At least $20 cut here.
  • Catching fish from a pond (or a friend's fish tank) and feeding food scraps. Duckweed can also be found in a marsh or pond. $30 saved here.
  • Scrounging around for shelving and vessels. Look around your house, at yard sales, Craigslist free section, and the side of the road. Be sure to clean whatever you find. If the shelving is found for free, expect to save $50- $100.

After implementing the cost reductions, this project would cost around $110. The components left out could always be upgraded or bought later.

Step 17: Thanks for Reading!

Thank you for taking the time to read through my ramblings! I really appreciate it. Aquaponics is a fun way to make the world a better place, and I hope all of you readers have gained some knowledge or inspiration from my writeup.

I'd love to hear your feedback, feel free to drop a comment! I'd love to chat or answer questions.

If you found this instructable useful, informative, or entertaining, I'd really appreciate a vote! This is my first instructable, so it will be entered into the first instructable contest, as well as the urban farming contest. Prizes will be put to good use!

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15 Discussions


3 years ago

Instead of a grow light, you could use blue and red 12V LED strips although this might not give off all the wavelengths needed.


Reply 3 years ago

I looked at a couple on amazon that claimed to have the correct wavelengths. They did look a little flimsy, and from experience I can say that most of the lower end LED strips have really flimsy construction. The tiny solder joints can fail and the little wires can fall off. However, LED strips would be very easy to mount and be better looking than the grow light. I was thinking about putting a strip above the fish tank as the fish are in a dim purple glow most of the time.


Reply 3 years ago

Perhaps you could use LED strips for aesthetic effect etc. and turn the grow light on occasionally to make sure everything's getting the right light.


Reply 3 years ago

I think I'll add an LED strip to my next amazon order. Might be cool to get a color changing one to shine in the fish tank.


3 years ago

That was awesome!


Reply 3 years ago

Much appreciated!


3 years ago

Really useful information, thanks for sharing!


Reply 3 years ago

Thank you!


3 years ago

I enjoyed your instructable very much very good!


Reply 3 years ago



3 years ago

Thank you for the highly informative instruction! I've been wanting to do this for a long time. How is your system doing currently?


Reply 3 years ago

The system is running fine at the moment. The kale seems to be growing, and the fish are happy. Best of luck in your adventures!


3 years ago

Very nicely done!


Reply 3 years ago

Thank you!