CHOP and FLIP' DIY Media Based Aquaponics System

The chop and flip DIY technique is often touted as the most simplest method when it comes to creating your own media based aquaponics system. That said, some might say that media based setups aren’t ideal for beginners since one stage of the filtration process requires special attention. However, there are several simple solutions for this, so any budding grower willing tackle the small additional DIY task can enjoy taking on a project that’s cost, space and time saving; all factors that are indeed beneficial for beginners.

These setups typically consist of a simple, three-stage system contain in three tanks, two of these are usually crafted from repurposed intermediate bulk containers (IBC) and then vertically mounted on top of each other to minimize the required floor space. Adding a smaller third tank, which houses the solid separator filter, completes filtration.

As long as you have access to the tools to ‘chop and flip’ an IBC (you could have a profession, or experienced friend do the work for you) then media based aquaponics setup are rather easy to build, especially since the plumbing network is also simple and easy to install. The only issue some may consider a problem is the solid separator filter; since the design doesn’t incorporate one in the base concept you’ll need to rig up your own.

With that in mind it’s not hard to see why so many growers have followed this popular method of constructing a DIY media based aquaponics system; not only does it result in producing and effective system you can set up anywhere in the home, or outdoors, it also looks the part; like a professional build but at a fraction of the cost.

In this article we take a look at how Rob Bob over at RobsAquaponics.com puts together his chop and flip media based aquaponics. All video and images are accredited to Rob: check out his Aquaponics website and informative YouTube channel >>>

How CHOP and FLIP' Media Based Aquaponics Works

As previously noted, the chop and flip technique refers to the construction method used to build this setup; chopping an IBC in two, using the larger part as the fish tank and flipping the other part to house the grow bed media and plants, which sits atop the fish tank.

In this setup the grow media doubles as home for the beneficial bacteria as well as the plants. The cycle starts in the fish tank where ammonia waste pollutes the water, which is then passed through a solid separator filter that removes suspended solids before the water is then pumped up into the grow bed.

As the grow bed fills, beneficial bacteria colonized on the grow media begin to convert the ammonia waste in the water into nitrates that feed the plants.

The plumbing network consists of a single water pump placed in the fish tank, and the bell siphon installed in the media bed to regulate the level of water. The water pumps provides a constant flow of water from the fish tank to fill the grow media, the bell siphon then drains the water periodically each time it reaches the top of the standpipe, where it is automatically released back into the fish reservoir to begin the cycle once again.

Planning Your First CHOP and FLIP' DIY Media Based Aquaponics System

Draft Plans

Building your own DIY media based aquaponics system might not being the most complex DIY project, it’s still a good idea to draw up some plans, especially if you’ve never build any similar systems. Having rough blueprints will give you a visual overview of the setup, which may allow you to spot any potential mistakes before it’s too late. The plans will also act as checklist you can use to ensure that you’re fully prepared, with both the materials and the knowledge, to carry out the next stage of the build.

DIY Pointers

The main hurdle you’ll encounter with this project is the repurposing of the IBC since it requires the use of power tools to cut through the metal frame. You can forego the power saw and use a hacksaw but there are a good 20 x 1” metal bars to cut through; no easy feat with hand tools.

Since the plastic used to make IBC tanks is typically opaque, you’ll also need to prevent sunlight reaching the water to prevent algae growth. We’ll look at several ways to achieve this, just note that you’ll need the space to paint, or the room and materials to build cover, and you’ll want to prep these tasks prior to assembling the final build.

Although the grow media sits above the fish tank reservoir you’ll still want to ensure that all plumbing is watertight. Many water pumps include piping that already feature watertight threads and connections, however it’s common that some connections will need waterproofing, so make sure you’re prepared with silicone/waterproof caulk, and silicone tape for any loose fitting threads.

Again, it’s a good idea to do this prior to final assembly. First seal any potential problematic areas then perform a test run with just a small amount water to help uncover leaks. Once the system is wet you’ll need to wait for the whole thing to dry before patching up any holes; a huge time sink if you happen to mix up the order of each step. Plus not all leaks happen immediately, some can take time to form, therefore it’s a good idea to prevent this issue before it ever happen.

PLEASE NOTE: All dimensions are only a guideline. Everyone’s situation; budget, available space, needs and requirements, are all different, and even using off the shelf parts/components, no two systems are likely to be exactly the same. So, proceed with caution, and at your own risk. DO NOT handle power tools if you have no experience, instead, perhaps you can turn to family and/or friends to try find a helping hand.

What You’ll Need

Once you’ve got a clear idea of how exactly the build will be done, you’ll need a list of materials and tools. To build the setup we’re looking at today, here’s what required:

Materials

Intermediate Bulk Container (IBC)
Kink-free, Reinforced Flexible Hose/PVC plumbing piping with valves, drainage, joints, connectors, etc.
Grow Media – for beneficial bacteria and plants (optional base layer)
Plastic Tank – for the solid separator filter
Mesh/Pond Fish Net/Sponge, Scourer – for filter
Stainless Steel Hose Clamps (optional, system dependent)

Tools

Angle Grinder/Reciprocating Saw/Power Handsaw/Hacksaw
Drill with Forstner bit for drilling large circles
Screw Driver (possibly with either T30, T40, Philips, and/or Flathead tips; depending on the design of the IBC)
Measuring Tape
Set Square
Pen (Marker/Felt, needs to mark plastic and metal)

Supplies

Silicone/Waterproof Caulk
Plumber’s tape
Adhesive (optional, design dependent)
Nuts and bolts (optional, design dependent)

Components

Water Pump (3000l per hour / 790 gallon per hour) magnetic drive pump
Bell Siphon

Fish Tank & Grow Bed

First the most crucial part of this process; ensuring the IBC is safe to use. Bear in mind that it could have been used to store all manner of harmful chemicals and substances, so stick with tanks that have only been used for food gradehttps://www.csidesigns.com/blog/articles/what-is-food-grade purposes just to be safe.

Using a standard 1000l / 265 gallon IBC, mark around the tank approx. 300mm / 11.8” from the top; this should be close to the 750l mark. Remove the two top crossbars of the IBC; these will likely be fastened with T30, T40, Philips, and/or Flathead screws. Put these bars aside as they’ll be reinstalled and used to support the bottom of the grow bed. If the small plate door is still intact also remove it and save to repurpose to protect the valve from ‘accidents’.

Remove the tank from the frame, then cut along the line to create two tanks of different sizes; the largest will become the fish tank, and the smaller the grow bed. It’s a good idea to grind down the ends of the metal bars to prevent injury and/or damage caused by sharp burrs. It’s also advisable to seal the ends of the bars to stop rust from forming.

Grow Bed

Reattach the frames to both parts, use screws if necessary, then reattach the metal cross bars to the top, flip it over, orientate it 90 degrees from the original position. This will provide an access channel through which you can reach the fish and insides of the tank. Then place the newly fashioned grow bed on top of your newly created fish tank, using a couple of planks for support.

Note: Pine is a popular, affordable wood often used in DIY projects, however pine is often comes pre-treated, and when used in conjunction with any liquids, can cause the chemicals used in the treatment process, to leach out into the system. For this reason it’s best to use untreated hardwoods.

This will create a grow bed that’s approx. 290l/76.6 gallons, which will leave roughly 50l/13 gallons space between the surface of the media and top of the grow bed.

Fish Tank

Shielding the System from Sunlight

As noted in the DIY pointers, although the video doesn’t provide step-by-step instructions on how to protect the fish tank from sunlight, it does mention how important this step is in order to prevent algae growth, and it does show a few examples of how to achieve this on a minimal budget. Some IBC tanks, namely the blue versions, feature UC protection, but if you’re using an opaque IBC tank then you’ll need to shield it from the sun.

The simplest, most affordable ways to do this would be to paint the exterior, build a wooden surrounding, or even cover the tank in or even build a brick wall should you want something more permanent and have the access/budget to the materials.

The large base becomes the fish tank, which will have a total volume of around 600l / 158 gallons. Here you’ll have the option to increase the size of the access channel by removing a row of bars along the top of the base, as you can see Rob has done in the vid.

Note: The valve sits lower that the base plate, if u decide not use the base from then you’ll need to ensure there’s space beneath it, which may require a small amount of excavation as shown briefly in one of Rob’s builds in the vid. Another clever little mod here involves installing the small plate door over the valve to keep it safe.

The fish tank itself need no further internal work, however it will house a pump to move the water up to the grow bed, and will be catching the run off from the grow bed once the bell siphon fires and drains the water.

Since many standard IBC tanks are opaque, you’ll need to construct something to prevent sunlight from reaching the tank.

Install Pumps

The system uses a 3000l/790 gallon p/hour magnetic drive water pump that runs around 85watts. All parts are readily available, which make installing the plumbing straightforward. The piping used is flexible, reinforced kink-free hose, and all irrigation connections are simple barb fittings, which in this model are said to be acceptably watertight. If your plumbing network isn’t watertight then you can use adhesive, waterproof caulk or silicone, or plumber tapes to help seal up any troublesome leaks. Stainless steel hose clamps can also be extremely useful if connections aren’t tight and/or pressure is too high for the staying power of the friction fit.

Most media based systems can run on the power provided by just one water pump. Water flow is then assisted by the use of a bell siphon, which regulates the water level in the grow bed.

A fantastic, extremely useful hack you’ll see Rob has modded onto his back yard setup; by using a slightly over sized water pump, which would typically be dialed back so as not to over pressurized the system, instead utilizes the extra power to redirected some of the water back into the fish tank via a small jet nozzle. This agitates the surface and aerates the water to increase the levels of dissolved oxygen; a task typically taken care of by features such as fountains, waterfalls, or even air pumps with an airstone, but that can be managed by a clever tweak that requires almost zero extra effort.

Bell Siphon

Coupled with the pump and responsible for regulating the water level in the grow bed; a bell siphon is then installed on the opposite side to the inlet from the water pump. Rob’s DIY bell siphon is constructed from a PVC pipes, with a outer shroud housing that keeps out debris, then an inner chamber and standpipe which make up the siphon device. The self-activating drain doesn’t require any power, and will work continuously without the need for much maintenance at all.

A bell siphon works by utilizing gravity. Inside the siphon is a tall standpipe, as the water level rises and reaches the top of the standpipe it begins to drip down, and as flow increases, the weight of the water becomes heavy enough to trigger the siphon action. This sucks all the water from the chamber, until the level recedes enough that air can enter the siphon from the bottom; which then turns it off.

With the right instructions bell siphons can be relatively easy to build, and Rob’s design is exactly that; simple and easy to build. If you like a step-by-step tutorial on how to put together a DIY bell siphon, then check out this video from Rob, or head on over to our article on how to build your own bell siphon drainage system.

Note: The height of the standpipe determines the height of the water level in the grow bed. It’s important to keep the surface of the grow media dry to prevent algae growth, and following Rob’s guide a standpipe 25cm in length will keep the water level in check. If that isn’t working for the dimensions of your setup then you can just make sure that the top of the standpipe is lower than the top of the grow media.

Install Filters

Built-In BioFilter Grow Media

One advantage of media based aquaponics setups is that the biofilter is naturally built into the design of the system from the start; eliminating the need to devise your own solution. One disadvantage however is that the solid separator filters are almost an after thought of the design, and will require some additional steps.

There are several options for grow bed media, in this video Rob uses clay balls, as well as rocks as a base layer. You can also use clay pellets, lava rock, and expanded shale. These materials are all suitable for supporting both plant life and the beneficial bacteria responsible for converting ammonia into nitrates to feed the plants.

It’s a good idea to wash the grow media prior to use. This just ensures no contamination can occur. To do this you can build a purpose build sieve, or you can simply use a wheelbarrow and pond fish netting as shown in the vid.

A system of this size can comfortably support around 10-12 fish; higher numbers will not survive due to the performance of the biofilter.

Simple Solid Separator

Whilst most consider the filter stage of media based aquaponics systems to be the most complex, especially the solid separator since the biofilter is taken care of by the grow media in which the plants grow, there are simple solutions that can reduce some of the difficulty.

When it comes time to build and install a solid separator, the easiest most simplistic way of achieving this is by placing scouring pads, or aquarium mesh blocks between the water pump outlet and the grow bed. Whilst not as effective as installing a separate tank, in which lots of pond fish netting/mesh can be houses, placing mesh in the path of the water can remove a good portion of the solids.

However, it’s likely this will not be sufficient and the water will need to be cleaned far too regularly. In most cases, you’ll want to install a stand alone solid separator, house in its own, small plastic tank or bucket, that is installed between the water pump and the grow bed.

Simple solid separates contain a series of mesh, pond fish netting, that capture and filters out all the waste solids in the water. A standpipe inside the filter ensures clean water flows from the top down into the grow bed, whilst all the waste sinks to the bottom. These types of solid separator filters need regular cleaning, but that can easily be done using the jet setting of a garden hose, or a lighter setting on pressure washer.

If you’d like an in depth guide on how to construct a DIY solid separator filter, then check out another of Rob’s informative videos ‘Solids Filter For Aquaponic System…’. In this tutorial he not only shows how to make your own DIY solids filter, he also shows you the simpler option of placing mesh in the path of the water, which whilst not advisable as a complete solution, is still nice to see the tip depicted on video.

Sump Tank

Should you wish to increase the production of your aquaponics system you can add more grow beds. This will require the addition of a sump tank; a common addition when expanding the area of the grow bed/s. Sump tanks ensure the water level of the fish tank stays consistent regardless of the flood and drain occurring in the grow bed. Sumps tanks work by essentially shifting the fluctuating water levels into a separate tank so the reservoir levels remain unaffected.

As a general rule of thumb sump tanks should be large enough to hold the total volume of water in the grow bed, this will roughly be 1/3^rd the total volume of grow bed media.

Conclusion

If you dive down the rabbit hole that is media based aquaponics one of the first things you’ll have likely come across is the claim that the technique is both suitable, and unsuitable, for beginners. Believing to have spotted the discrepancy, it would seem that the filtration system of media based aquaponics could potentially present some hurdles for the inexperienced. However, a quick search further afield suggests that taking a basic approach in constructing the filtration system is in fact possible, therefore building a DIY media base aquaponics system with little to no experience is also possible.

Media based system provide a number of advantages, which include: a low risk of disease, supports a more diverse plant selection, more stable and resilient, and simple to set up. Perhaps more importantly, they make it easy as can be to raise and harvest both fish and plants in a single system, that requires minimal effort when compared with traditional farming techniques.

With that in mind it’s safe to say that media based setups truly are some of the easies to setup, monitor and maintain, so if you’re looking to get your feet wet by finally make the jump into the DIY aquaponics realm, then kicking things off by building a system exactly like this is a great place to get started.

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