Organic Hydroponics / Aquaponics




Aquaponics is the commingling of Aquaculture, a.k.a. fish farming, and Hydroponics, growing plants/crops without soil. This instructable will show you a simple method of growing both fish and plants, using easily obtained and/or household items, for enjoyment and beauty or for consumption.
Why should you care?
Aquaponics (AP) is easy and has been used for thousands of years (from Chinese rice paddys to the Aztec water gardens), can be practiced on any scale, consumes approximately 1% of the water in a traditional growing system, and is a great way to learn about closed-loop systems and ecology.
AP can help feed families in dire need of nutrition, with agricultural crops; but also with much needed proteins in the form of fish. This example isn't exactly what a poor family in a third-world country might put together, it is exactly as stated; an example.
The entire earth is (more or less) a giant aquaponic lab; but we're going to start small, in the living room.

Step 1: What You Need

I'm using a simplified "S&S Aqua Farm" version of Aquaponics. I'll go over some different thoughts on AP and different styles of systems towards the end of this "ible."

Tools needed:

Rubbermaid Roughtote 18-gallon storage bin.
~18-gallons of water
~8-gallon "under bed" style tote.
~8-gallons of "pea gravel"
~4-ft of 1/2" tubing
2-liter bottle
End cap for tubing
~200-gallon/hr water pump with control valve (less is probably fine with a system this small)
On/Off timer with 15-minute intervals
Freshwater aquarium water tester (strips or kit)
Fish (I used 3 goldfish and a crayfish)
Seeds for planting (Fruiting or non-fruiting, lettuces, wheatgrass, it's all good)
Short stand or table that can hold ~80lbs or more.

If you had to buy everything for this as new, it would probably cost ~$30US including the fish and seeds but excluding the stand/table and test strips. As it is I had everything on hand except the pea gravel, so this cost me about $0.75 to make.

Options (not necessary for the purpose of this Instructable, but very valuable additions to AP in general):
Aquarium heater
Uninterruptable Power Supply (battery backup)
Grow lights, CFLs work fine (if growing away from sunlight)

Step 2: Cleaning Gravel

This is the true grit, the right of passage for any AP system keeper. You must now clean your gravel. It is very rough going, i used a big colander and several batches of gravel under a hose, and more in the bathtub, and it still wasn't clean when i added it to the grow bed.
You can avoid all this by using LECA, expanded clay aggregate, a.k.a. Hydroton, instead.
Hydroton is also much lighter than pea gravel, if you can afford it, definately go for the Hydroton.
Otherwise, GET TO SCRUBBING!!!

Step 3: Put It Together

Basically, you want the growbed, filled with gravel to sit partially above your fish. For 15 minutes, the pump pushes water above the tank and into the grow bed. The grow bed has holes on the bottom corner that sits above the fish tank, emptying back into the tank.
We achieve this by using the Dremel to drill 16 1/16" holes about 1/2" apart on the bottom of the under-bed tote(grow bed). We also drill 8 1/4" holes near the top of the grow-bed to save overfilling the bed and flooding the living room! Hold the Dremel in a way that you are drilling from the middle of side that is over the fish tank, if you drill from the center the water will pour out of the grow bed towards the middle, also saving you from flooding. Also, drill at least 4 1/8" holes on the upper rim of both sides that are perpendicular to the side over the tank, directly across from each other; these will help secure the tubing later.
Place the roughtote on the floor, next to the stand that holds the grow bed and fill it partially with water. Hook the tubing up to the water pump and place the pump inside the tank, with the other end of the tubing securely in the grow bed. Make sure the grow bed is hanging over the tank in a way that the water will empty back into the tank, and plug-in the pump. Adjust the pump's control valve to slow water uptake as necessary. When you think you've got it close to perfect (water rises in the grow bed to the 1/4" holes, but not past), unplug the pump.
Fill the 2L bottle with water and cap it; place this on the side of the grow bed where the drainage holes are drilled. Then fill the grow bed with your washed (and re-washed:) gravel. The bottle is there to protect your drainage holes from the root structures of the plants you'll be growing. Those roots will plug the holes and you'll have another potential flood in the room.
Place tubing over the gravel. Using the scissors, cut the tubing at the far end of the grow bed and use the end cap to, uh, cap it. Drill 5 or 6 1/8" holes all the way through the tubing, spaced along the length of the tube. Using the twine (will eventually rot, break, and need replacing), tie-down the tubing so that it doesn't move when there is water pressure.
Time to test the pressure on that pump again. Adjust it as necessary.
Take the lid from the roughtote and cut enough space out of it to allow your water to fall through, but retain the handles and connect the lid to the roughtote for extra support. I also use the cut-out portion laid across the top as a splash guard.
Congratulations! You're done with the construction part of this "ible."
However, DO NOT PUT FISH IN IT YET!!! Doing so will almost certainly kill them.
Next step will get into some specifics on how this whole thing works...

Step 4: How AP Works

Aquaponics works in a similar fashion to freshwater aquariums with "biological" filters. We're taking the bio-filter concept and expanding it. Similar to a new aquarium, a new AP system needs to "cycle." Cycling is the means by which we start the "Nitrogen Cycle" (a.k.a. nitrification process, start-up cycle, biological cycle). This process adds ammonia(NH3) or ammonium(NH4) to the water in order to start the colonization of beneficial bacteria in the filter. In AP, the aquarium can be any tank that holds water and fish and the filter is a grow bed where crops are grown. Two types of bacteria colonies emerge, Nitrosomonas and Nitrospira. Nitrosomonas breaks ammonia down into nitratis, through oxidation, effectively cleaning the ammonia from the water. This would be a problem, as nitrites are just as poisonous to your fish as ammonia, if not for the development of the second beneficial bacteria. Nitrospira form and turn the nitrites into nitrates, again cleaning the water. What is left is easily consumed by growing flora, completing the cycle, and returning clean, safe water to the resevoir (fish tank/pond).
The cycling process can take anywhere from 2-3 days to 2 months (I've never experienced anywhere near that long, but supposedly it can happen). Test your water every couple of days for PH levels, and most importantly, for Nitrite and Nitrate levels. You will initially see a spike in Nitrites, then a spike in Nitrates as the Nitrites decline. When the Nitrates begin to rise it's time to add some flora to your grow bed. Your plants will happily consume the Nitrates through osmosis and the cycle is complete. There are several ways to begin cycling an AP system:
1. Put fish food or raw shrimp or other grocery store fish in the system, they'll begin breaking down into ammonia (or ammonium if your PH is low [~6 or under]), which will start the forming of bacteria.
2. Buy some 100% Ammonia at the store and add a bit (depending on the size of your system) every couple days.
3. Pee in it (probably not a good idea if you're on medications, narcotics, or are a heavy boozer).

Notes on speeding up the process: Using biological addatives such as "Colonize" or "Stress-Zyme", or filtration material or gravel from a mature AP/aquarium that is already colonized can greatly decrease cycling time. Increasing water temperature to a tepid bath (82-84F) and keeping the water pump on 24/7 is probably a good idea as well.

You also may have noticed that I'm not using any air stones and air pumps. For this style of aquaponics it's unnecessary unless you're stocking a LOT of fish. In a flood and drain system such as mine, the grow bed acts as a piston pushing old air up and out of the grow bed, and pulling fresh air in when the water level drops. This brings plenty of oxygen to the root systems of the plants. The water splashing back down to the fish tank incorporates into the water all the air your fish will need. So there is no need for an air pump.

You are now ready for the final step:

Step 5: Fish!

With this small setup I didn't want to go overboard with my fish. I stuck to 3 goldies and 1 crayfish. It's enough effluence to keep the small grow bed in nutrients, and enough grow bed to completely clean the water. I have my timer set so the pump is on for 15 minutes, then off for 15 minutes all day long. It's a perfect balance for what I have setup. That doesn't mean that there are hard and fast rules as to how to stock, how, or even IF to flood your growbed, or how to empty it. This is a simple example of this style of AP.
For this type (S&S Aqua Farm style) AP system, the stocking density and growbed to tank ratios are generally quote as 2:1 grow bed to tank and 1 pound of fish per 2 gallons of water (Note that this is an extreme in intensive aquaponics that is not recommended without extreme care and air pumps and stones). That doesn't sound to me like it would make for happy fish; but if you're in need a LOT of fish and crops, those are the limits.
I usually plant half of the grow bed at a time, so that when i harvest one side, the other side is still cleaning the water for me. I believe this is baby arugula i have growing in this pic.
There are other styles of aquaponics, some can be seen here at Instructables, others can be found all over the web. My personal favorite site for AP is They have a wonderful forum of immensely knowledgeable people. Please visit there and buy the book, if you're into that sort of thing!

This brings us to the end of this instructable. I hope you enjoyed and will give AP a try! Expect a more elaborate "ible" on a much larger AP system in the near future...

Participated in the
Epilog Challenge



    • Sensors Contest

      Sensors Contest
    • Planter Challenge

      Planter Challenge
    • Growing Beyond Earth Maker Contest

      Growing Beyond Earth Maker Contest

    22 Discussions


    3 years ago

    I just want to know about the ratio between fish tank area and green field. Please help me if any body have the proper methodical calculation.

    Biplab Tah : (India) 8170018080 e-Mail :

    jimmiekGhost Wolf

    Reply 7 years ago on Introduction

    I have an extra 20 gallon tank and raise guppies, I throw some into the tank evey few days - you should see the Tilapia go after them - a couple of dozen guppies can disappear in seconds - those that make it to the floating guppy grass don't come out often! Other than that. I feed them a High Protein, High Fat commercial fish food (no chenmicals or mendicants) so they are as organic as possible! They reach market weight (1 to 1 1/2 lbs) usually within 6 to 9 months if I am diligent enough to separate the males from the females. The females grow at a much slower rate if they are allowed to get bred as they hold the eggs/fry in their mouth for 2 - 3 weeks without eating! and they can breed again within a week or so after letting the fry out on their own if they aren't watched closely.


    10 years ago on Introduction

    "1 pound of fish per gallon of water. " That is WAY WAY too much fish per gallon of water. The rule of thumb is 1 inch of "slim bodied fish" (like a danio) per gallon of water. And your goldfish need 5 gallons per inch of fish as they are high-waste producers. I'm surprised the author didn't know this as s/he seems to understand the cycling process.

    4 replies

    Reply 7 years ago on Introduction

    It all depends on what you're doing with the fish and fish tank. If you're running the water thru a growbed, (biofilter) and changing the water 6-7 times an hour (350 GPH pump with a 50 gallon fish tank and 100 gallons of growbed), it's fine to have that kind of GPF, but if you're just using them as aquarium fish, you're going to kill them with that kind of GPF. Raising plants and fish in AP is a whole lot different than having an aquarium in your living room to look at and enjoy all the cute tropical fishy's! Goldfish (carp) are a two-year grow-out to get them to market weight, Tilapia are 6 to 9 months! 5 gallons of water per inch of fish would bankrupt an AP producer - that's not being realistic! Read up on what professional fish farms are doing, don't go to Petco for info, those little books are for persons raising pets at home, not for AP farmers or pros! AP fish farmers don't raise the fish to look at, they raise them for food! I don't know too many AP fish farmers that eat Danios ;>) I guess I should have specified that we use high capacity pool pumps, not aquarium filter pumps that are more like 20-30 GPH if you're lucky :>)
    I might also mention that we drop the water into the FT from the GB since it picks up oxygen when it is splashed in rather than pumping it directly into the water via a pipe and then trying to add air with airstones, etc. We drop it from one GB to another, picking up oxygen along the way. Our fish are not stressed, nor are they lacking oxygen.


    Reply 10 years ago on Introduction

    Actually I was wrong and edited that section. The correct ratio is 1 pound per 2 gallons; but I also noted that it should be avoided. My original did note that I didn't find that acceptable, and my density is dead on with what you mention. That 2:1 growbed/tank and 1:2 lb/gallon are ratios for very intensive farming meant to feed as many as possible with as little as possible, and is done successfully with tilapia in the Caribbean.


    Reply 10 years ago on Introduction

    Sorry, I didn't know that stocking level was for intensive farming methods. That would certainly be different from the casual hobbyist due to different methods of controlling waste.


    8 years ago on Step 2

    Hydroton is not that fun to clean either. I ended up nailing together some 2"x4"s into a 2'x3' frame and skinned one side with wire mesh/screen with holes just smaller than the Hydroton. Like a flat colander. It sits on my wheelbarrow and now I have a screen to filter my compost, too. I bought a small pressure washer just for tasks like this. Makes cleaning sooooo much easier and faster. Good luck and thanks for the info. It's been almost 2 years, how's it going?

    Rune Cutter

    9 years ago on Introduction

    Hey bhsx, thanks for hitting my reset button, I looked into this a couple of years ago and then let it go, getting ready to fire up with tilapia and maybe red claw crayfish, waiting on compatability info, I may have to sextion of the tank, looking into muscles too but it may be to hot for them in West Texas.


    9 years ago on Introduction

    I do aquaponics in the summers here in Montana, the 2:1 ratio of growbed:FT is right, however, when you have the right GB/FT ratio, the amt. of fish/gallon can be increased. I had 200 fish (Guppies) and 4 crawdads in a 50 gallon Rubbermaid tank with about 100 gallons of growbed all summer long ..... it worked fine for me ;). The amt of danios/gallon is for a regular aquarium, not for an AP system. Don't let anyone snow you bhsx, what works fine for you is right for you I have 1 pound of fish (tilapia) to 1 gallon of water right now with a biofilter acting as a growbed! ....... Great Instructable to let newbies know about AP!!


    10 years ago on Introduction

    blaghh i hate arugula, :) great idea, doubles as a filter and veggie farm


    10 years ago on Introduction

    thanks for your instructible.. I'm digging up all the info I can.. and this will come in very useful...


    10 years ago on Introduction

    I thank you, and wish you well on your next system. I think your fish tank is understocked. the one I am building is 300 gallons fish water and 150 gallons grow bed. I plan on stocking 100 tilapia fry, after cycling the system. I have personally seen great systems running at lower stocking rates, in Main, of all places. Oxygenation is required. The more fish the better in my opinion, with the appropriate grow bed area. Thanks for letting everyone know that washing your gravel is necessary. Many have tried to start a system without doing that and failed miserably. I will post with photos as I get things running. Food for all and all for Food. good work, thanks again, AV

    1 reply

    Reply 10 years ago on Introduction

    Hey great to meet you AV... What are you using for your tank? If you're in the US I'd guess a Rubbermaid 300-gallon stock tank... If so I've been eying those for a while! Yeah, my tank is understocked. This was my first attempt at AP as a demo for the family, it was successful enough to "get permission" to build a "real" system when we move. So I'm happy with the results! Please do post some pics and maybe a full instructable if you get the chance... Take care.


    10 years ago on Introduction

    China is currently suffering it's worst drought in half a century. It's farms are using 2/3 of of it's water supplies and are not that efficient. "Notoriuosly inefficient " is how they were described in NewScientist 21st Feb 2009. L