If you are someone who engages in aquaponics and is also an environmental enthusiast, I bet you have already considered this question: Are there organic or recycled alternatives to using as floating rafts for aquaponics? Today, I am telling you—there’s plenty!
Alternative to the polystyrene styrofoam, aquaponic floating rafts can also be made from 1) recycled plastic, 2) wood, and 3) bamboo. Moreover, a mushroom-based aerated bed system can also be used as an aquaponics raft.
I know what you are thinking: How to use these materials? Can I DIY? Should I submerge these materials in water? Are there ways to prevent them from degrading since they are biodegradable? Well, reading forward is the best action you can do for now.
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Styrofoam is used in aquaponics because it is a cheap and accessible choice. However, concerns of food safety are entangled with it since it is made up of polystyrene.
Before we start, let us recall the role of floating rafts in aquaponics. Its major role is to contain the plants. They are usually boards with holes that hold net cups where the plants are grown. They are usually used in a deep water culture hydroponics and aquaponics.
They are usually chosen because of their cheap price and accessibility. Prices of styrofoam sheets on Amazon only range from $14 to $24 for packs of 2 up to 7 pieces. This is much cheaper compared to pre-made traditional floating rafts that cost $50 each.
On the downside, styrofoam sheets are made up of plastic #6, also known as polystyrene, can have long-term health effects. It is also believed that even though it comes in small amounts, it can still leach out of containers, making it a hazard for plants, fishes, and humans.
Another concern is its environmental impact since styrofoams are non-biodegradable.
Experts have recommended plastic #2 (high-density polyethylene) and plastic #5 (polypropylene) as the safest option for hydroponics utilization.
Aquaponic floating rafts can be made of plastic bottles or PVC pipes.
If you are a fan of DIY, this is good news! You just need a hole driller, or you can use a soldering iron to make holes in PVC pipes.
The figure below illustrates a possible design that you can adopt if you are planning to make a aquaponics raft from plastic bottles and PVC pipes.
A creative way to use PET bottles and PVC as an aquaponic floating raft is demonstrated in this video.
Plywood can be used as rafts as long as they do not touch the water or they are coated with waterproof paint free of toxins.
Using wood needs extra caution since it can degrade if submerged in water. A strategy you can do is to just let the plywood sit on the edge of your hydroponic tank. After that, you can drill holes that fit your net cup. Lastly, estimate and adjust the water level based on the position of the plant roots.
If you want it to float, you can also add plastic bottles below the wood board to support buoyancy. You can also paint the lower portion of the wood with waterproof paint or clear varnish, to protect it from destruction by water.
Remember that a wet wood can support the growth of microorganisms such as fungi or bacteria that can both be harmful to your plants and fishes.
Bamboo is a good floater, thus it will be fit for an aquaponics raft system. Bamboo can easily be shaped using a saw or a bolo.
Several aquaponics practitioners saw the potential of bamboo as a raft. Here are some methods being practiced by aquaponic farmers.
- Take a bamboo that is 8 to 10 cm in diameter.
- Cut the bamboo in your desired length that will fit your aquaponic system.
- Slice the bamboo culm in the middle using a bolo or a saw.
- At the lower part of the concave bamboo attach plastic bottles perpendicularly using ropes to upgrade the floating mechanism.
- Using an electrical hand saw or a hole driller, create holes that can fit the net cups, where your plants will be placed.
Another idea, which is less laborious is just positioning bamboo sections such that each space can handle the net cup. This is illustrated in the figure below.
Ecovative Design introduced MycoComposite™ which is a novel form of wood made from mushrooms. One of the applications of this product is aerated bed systems, which can be used as rafts for aquaponics.
This is engineered to be a viable, durable, and novel source of wood. The wood is composed of mycelial products, which means produced by mushrooms, combined with agricultural and wooden substrates. These materials are then bound by resin that strengthens the product.
Styrofoam is safe to use in aquaponics but extra measures must be done. They must not be exposed to high temperatures as this can result in the release of toxins.
Although the use of styrofoam in hydroponics and aquaponics has been supported by the Food and Drug Administration already, we still need to look out for certain factors that can harm our system.
It is important for aquaponic growers to maintain a cool to moderate temperature when using styrofoam. Above the boiling point, styrofoam can be subject to chemical leaks that can harm your fish and plants. Thus, daily monitoring of water and the surrounding temperature is highly advised.
- “Is Polypropylene a Safe Plastic to Use in Your Home?” by Stanborough, R.J. on Healthline
- “MycoComposite” by Ecovative in Ecovative, The Mycelium Technology Company
- Scaled Growth and Production of Mycelium Resin for Low Density Engineered Wood by Mcintyre, G. R. in USDA Research, Education and Economics Information System