How to Build DWC Aquaponics System: Aquaponics DIY Series
Deep Water Culture, also known as the Floating Raft system, is generally considered the most effective aquaponics technique on the market. Utilizing deep water channels, upon which floating rafts and pot nets support the plants, DWC systems provides efficient use of water and superior uptake of nutrients. DWC systems are relatively straightforward to construct, grow beds can be built as large spacious flat tanks, or stacked vertically to maximize yields no matter what space you have to work.
Here we’ll take a look at creating your own DIY flat bed DWC aquaponics system made from wood. Recent lumber prices reached an all time high in 2021, and in 2024 the cost still remains relatively high. So if you’re presented with the opportunity to use reclaimed wood for part of the build, go for it. Nevertheless, despite the increase cost of materials, DIY wooden DWC grow beds are still a viable option.
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Planning Your First DIY DWC Aquaponics Floating Raft System
Once you’ve decided that DWC is in fact the technique for you, the very first thing you’ll want to do is to draft up a floor plan depicting where you want everything to go. The setup comprises of three main structural sections…
>>> Fish Tank > Mineralization/Filtration Tank > Grow Bed >>>
… each of which is connected by a network of PVC piping and pumps so water can circulate through the system.
Additional components/parts include:
- Water Pump (optional, system dependent)
- Air Pump (optional, system dependent)
- PVC Piping
- Net Pots (with grow media)
- Mineralization/Filtration system (biofilters, solid filters)
- Grow light (optional, depending on location)
Drafting Plans For DIY Floating Raft DWC Aquaponics System
With your design in mind, you’ll want to draft up some rough plans; start by accurately measuring the space and carefully sketching the placement of each section. NOTE: Pay special attention when noting the distances between each part; these will be connected by pipes that must be accurately cut to size.
Those with limited space to work in may wish to opt for a compact, vertically stacked configuration, whereas those with lots of room may prefer a open, separated setup.
All-In-One Modular Design
Here you’ll have the option to construct each section close together, right next to each other, or even stacked vertically on top of each other. Opting for this all-in-one, modular unit may be more suitable for aesthetic purposes, and will no doubt be the best solution when setting up in the living room or kitchen.
This option is typically more demanding in its design and construction requirements, and therefore should only be undertaken by those with lots of experience woodworking. If this sounds like an ideal project to start your aquaponics journey, then our suggestion would be to analyze other pre-built, complete systems from reputable brands, choose the most suitable design feature, then put together your own custom setup specially created to meet your requirements.
Multi-Part Design
If on the other hand, you’re not limited by space, separating each section offers a number of benefits.
For example, not only will the construction be simpler and cheaper, it’s also easier to build large grow beds that can hold hundreds of plants, and this spacious layout allows easy access to all components; a highly important factor since proper maintenance can literally be the difference between thrive or survive.
This, less complex approach is more straightforward to construct and can be done by anyone comfortable with power tools with a little experience in woodworking.
Sketch out your chosen configuration and take measurements for the plumbing network.
Regardless of the configuration, all Deep Water Culture/Floating Raft Aquaponics systems will utilize similar components, the only differences may come down to the type (air/water) size, number and placement of the pumps. The volume of water, together with its path, will determine what pump requirements are necessary. Systems can utilize water pumps, airlift pumps, and gravity to move the water, whereas air pumps are used to aerate the water being connected to an air stone.
In this example we’ll be installing an all-in-one mineralization/filtration system, and we’ll be constructing the grow beds out of wood. Timber and panels come in lengths of 8ft, with panels being 4ft wide, so we’ll be sticking to divisions of 4 to keep construction simple.
“Everything you need to know about constructing your own DIY DWC/Floating Raft aquaponics"
How To Build DIY DWC Aquaponics Floating Raft System
It may go without saying, but just in case, these components will carry moving water, therefore the whole system not only needs to be completely watertight, it must also be strong enough to hold the weight of the water, plants and the floating rafts.
Fish Tank
To begin drafting up your construction plans, you can start with selecting the most suitable fish tank. It’s common to use off-the-shelf, pre-built tanks for this purpose; rain water tanks, plastic barrels, plastic, fiberglass, or even glass tanks are typically easy to find, and inexpensive (search on the used market for affordable glass tanks).
Mineralization/Filtration Tank
Another component that can be easily placed a various size/shape of tank, or even purchase as a complete unit, Aquaponics filters systems are comprised of two stages, biofilters; that provide the substrate for beneficial bacteria to bloom, and mineralization tanks; that separate and break down solids, then converting fish waste into useful nitrates
Here opting for pre-built units, or purpose built aquarium parts may make construction easier as pumps and piping connections will have already been taking into consideration. However, simple plastic tanks can be rigged just as easily with the right cutting tools, so don’t be put off if pre-fabricated tanks are out of budget.
Note: The total efficiency of the filtration is a spec that doesn’t necessarily get overlooked, but can be difficult to get right the first time. In some cases this can leave the system lacking in surface area, which the bacteria need to colonize. Unable to thrive in mass numbers, the lower concentrations of bacteria can have devastating effects on the ecosystem, and therefore must be corrected to ensure levels stay balanced so plants and fish can thrive.
Plumbing/Piping Network
Plan out the connecting network of pumps and PVC piping; note down the number, and type, of joints you’ll need to connect each section.
Water Pumps or Air Lift Pumps
With visual plan you’ll be able to see exactly how many pumps you’ll need. Once you’ve calculated the total volume of water, and how high/far it needs pumping, you’ll be able to narrow down what specs pump/s must be installed.
Air lift pumps are common alternative for some growers. Although they might not be as efficient in overall output, they are more energy and cost efficient, and can be easily installed.
Air Pumps
With some back of the napkin math’s you’ll also be able to figure out if additional air pumps will be need to aerate the water sufficiently so the fish can thrive. If you’re unsure, or you plan to upgrade and expand the same system in the future, then just be sure to think ahead about how and where additional air pumps can be added.
In addition, you’ll also want to install an air pump and air stone in the tank to aerate the water and provide enough dissolved oxygen for the system. Be sure to consider, where and how you’d do this; air pumps typically sit at the bottom of the tank, where they pump water through and airstone to create bubbles. Once things are up and running you’ll then be able to analyze the DO levels in the water to see whether or not extra air pumps are required.
Plant Grow Bed / DIY Tank
In order to maximize the yield from the plants, the grow bed will be the largest part of any DWC system. For this reason buying prebuilt tanks isn’t really a viable option, instead it’s common to construct your own DIY Grow Bed and Tank.
To do this you’ll need:
- Wood Frame Timbre
- Wood Paneling/Alternative Paneling
- PVC/Vinyl/Waterproof Lining
- Wood Screws
- Silicone/Waterproof Caulk
- Table Saw/Circle Saw/Hand Saw
- Drill
- Screw Driver
- Measuring Tape
- Set Square
- Pencil/Pen
A few DIY pointers...
Although the project falls perfectly under DIY, you could get a professional, or qualified family member, friend or acquaintance to build the grow bed for a fee. You may even be able to find prebuild, and/or custom components that can be repurposed, but no matter how pre-built your components are, or how much assistance you received in the construction of your setup, it’s almost guaranteed you’ll need to perform your own repairs at some point, which means you’re going to need some tools.
We’d at least advise getting yourself a drill, powered screw driver, measuring tape, set square and a collection of screws, as well as some waterproofing caulk, silicone or other waterproof sealer, just in case any emergencies require immediate attention. For the most part this short list of tools and supplies will typically suffice. However, should ur situation warrant such a purchase, you may find that laser cutters, water jet cutters and CNCs can greatly expand the capabilities of building larger, more commercial and/or high tech systems.
Choosing Species of Wood
The species of wood you chose will largely depend on your location, which will determine what types are available at what cost. You should be looking for an inexpensive hard word, preferably local for sourcing/sustainability reasons Popular woods used to build aquaponics frames include:
Frame Timber Planks
Pine (untreated): Popular softwood for furtniture making; pine is affordable, strong and easy to work. It’s best to ensure any pine used for aquaponics is untreated, as pieces that have undergone treatment can leach chemicals into the water. Although the water in the system will not be directly exposed to the pine, as it will be held in the tank by a waterproof lining, it’s still good practice to use untreated pine so you can avoid these risks completely.
Maple: A popular hardwood for furniture building, Maple is extremely durable but a little more expensive than pine.
Oak: Another popular hardwood for furniture making, oak is slightly weaker than maple but still extremely durable
Floor Panels
Plywood: Best value for money. Readily available and relatively inexpensive, plywood is not only sturdy; it’s actually lighter than solid wood.
Medium Density Fiberboard (MDF): cheaper than plywood, but less durable, and more susceptible to water damage.
Oriented Strand Board (OSB): also known as Strand Board, Wafer Board but NOT Chip Board.
Low Density Fiberboard (LDF): aka Chip Board, Particle Board.
EKO Ply: environmentally friendly plywood made from recycled materials.
Solid Wood (reclaimed): Whilst the real thing fresh out the wood yard will no doubt run you a few more readies, reclaimed wood is common in many areas, especially when you’re willing to put in a bit of a work to repurpose scantlings, planks, balks, battens, and boards.
NOTE: Good, clean, large panels are one of the hardest cuts of reclaimed wood to come by, so any ingenuity here that cuts down on cost but gets the job done will be a welcome addition.
Dimensions
If you’re buying materials from any standard lumber supplier/timber yard, you’ll find that planks and boards of timbre measure 8ft in length. For this reason it makes sense to construct your grow bed in divisions of 4ft or 8ft. Of course this is just a guideline, you can make the bed any size, sticking to divisions of 4 keeps things simple and produces minimal waste.
One crucial point to note is the true dimensions of the classic 2×4 plank; these actually measure around 3-½ inches x 1-½ inches, not 2×4”. In the past the 2×4” were indeed true, however most timbre is now milled and planed, which removes around half an inch. By the time this became standard practice the term 2×4 had already found its way into the language as a popular colloquialism that still remains to this day.
When marking the wood for the supports, be sure to take into account the thickness of the 2×4”. Since this comes in at 1-½ inches, you’ll need to add ¾ inches inches to ensure the screw is centered in the support. This spacing provides a huge advantage as it allows two panels to be held by support; the simplified design is not only easier and takes fewer steps to put together, it also adds further stability to the structure ensuring the pieces are configured in the most efficient, sturdy way possible.
Lay Foundation Frame
To being construction you’ll need to level the ground so you can lay the frame. If you’re setting up on dirt or soil you can drive supports and side panels down into the ground. If you’re setting up on concrete or any solid flooring then it’s a good idea to raise the whole tank off the ground using bricks (as shown in the image). Two paving stones or bricks is a good height; this lifts the bed to prevent it sitting on the floor where water may pool up, it will also allow you to run piping underneath the tank, and make the flooring a bit more accessible.
- Length wise, for our example, we’ll be shooting for 8ft x 4ft wide. The structure will need support studs every 16inches, which for 8ft = 6 studs.
- The studs should be cut to 45 ½ inch, just shy of 4ft. This allows the floor panels to sit on both sides of the frame walls for maximum support. It also leaves ¼ gap either side where you can run tubing, or simply have a little a play, which isn’t a bad thing in this instance.
- Remember to account for the thickness of the 2×4 when marking the distance between the studs. To do this mark the outside of the next stud at 16 ¾, this will center the plank at exactly 16inches; allowing space to support two floor panels where they meet.
When it comes to joining the lumber, you’ll find a variety of screws suitable for the task. Simply ensure they’re wood screws, and are not longer than the thickness of two planks, so they do not penetrate the other side of the wood and risk puncturing the bed lining. Although self-tapping wood screws are not self-screwing by definition, they do not require a pilot hole since wood is a relatively soft material. However, if you’re having difficulty driving screws into the wood then try drilling pilots first to see if that helps.
Add Border Frame
To provide support for the walls, and to strengthen the overall structure, you’ll need to add an additional frame around the bed. To cover the full width of the base the sides must be 3 inches oversized @ 51 ½.
This means you’ll need additional 2 lengths of 2×4 @ 8f, and 2 widths of 2×4 @ 51 ½ inches.
Lay Floor
Next you’ll want to lay the floor. Here 8x4ft chipboard panels are ideal. Simply slide them into the place and fix with screws. Be sure to leave a ¼ channel either side.
Note: You can further apply the concept of lateral support braces to the floor the frame. The more lateral support the less you need to worry about the strength of the floor panel.
Construct Sides
Then you’ll need to construct the sides. This can be done from 2×12 boards (or 2×10 but not smaller), which can be fixed to the grow bed using vertical support studs, also 16” apart (as shown in the pic. Image credit: New Agrarian). The vertical supports will be the total of the board and the frame @ just over. 13inch.
Finally cut a drain hole in the bed, even if you’re initial plan doesn’t plan to utilize this type of draining you may wish to in the future.
With the base basically complete, you can further seal the sides with caulk or silicone. You should also do a once over the whole bed for any sharp points; you can then cover them with duct tape or sand them off all together.
Line Grow Bed
Next you’ll need to install the lining of the bed. This is actually easier than it sounds, if you use water to help push the lining flat to the surfaces and flush into the corners. Simply roll out the lining so it fits neatly in the bed. Then begin to fill the bed with water. The water will push the lining flush with the tank.
To fix the lining, drap the sides over the walls, then attach some planks of 2×4 along the top of the wall to secure the lining in place.
Install Plumbing
The last thing to do is install the plumbing. Using off the shelve PVC piping will make this job as smooth as possible since all junctions and connections will be water tight, or easily made watertight using silicone tape.
Install Mineralization/Filter Tank
MDC 1000 Aquaponics Fish System Mineralization TankOpting for the DIY method to construct the filtration system is perhaps the most complex part of the build. In the future we’ll take a look at exactly how to put together your own filter/mineralization tank for DWC aquaponics. But in the interested of simplicity, when it comes to installing filtration in your system we highly advise beginners to check out all-in-one, complete filter systems such as the ATS MDC 1000 System. These units are essentially plug-in-play, and take care of all filtration needs.
In Conclusion
Building your own DWC/floating raft system aquaponics setup may initially seem like a huge undertaking. However, once you analyze and breakdown each step, you’ll find that, although it is by no means a quick DIY project, it is actually quite straightforward.
With DWC aquaponics representing the most effective way to harvest the biggest yields, whilst also providing the option to install vertical grown beds in restricted spaces, or large flat grow beds in greenhouses, or dedicated grow rooms, the versatility of these setups can make them an ideal choice for most growers looking construct their own DIY aquaponics systems.
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