Is PVC Safe for Hydroponics? Behind the Safety of These Plastics

A lot of us are currently turning towards growing our own food, planting vegetable crops that are easy to grow and maintain. But because of the limited space homeowners may have, they look into other ways to grow their vegetables. One excellent method is hydroponics, which is a planting method using nutrient-rich water solutions as a base for your plants to grow.

Compared to traditional soil-based planting, hydroponics is a great method for plant-growers as it allows them to control and regulate variables based on the specific plants’ needs for better growth. That is why it’s important to use the right materials for hydroponics, which is another crucial factor one should consider when installing the system.

Which brings us to the question: Is PVC safe for hydroponics? Read on to find out!

is pvc safe for hydroponics

Is PVC Safe for Hydroponics?

Many gardeners with hydroponic systems are looking into using PVC for various reasons, such as:

  • PVC pipes are very affordable compared to other plastics, yet still durable
  • They are pretty efficient, as certain types are light, resistant, and flexible
  • PVC is versatile and can handle various weather conditions, whether indoors or outdoors
  • There are a variety of configurations to customize according to your hydroponic system

There are different kinds of PVC, with some of them not suitable for a hydroponic system. It’s important to know which PVC materials are better suitable for hydroponic systems, and which are the ones to ignore. These are the various strains of PVC:

  • Plain PVC comes in two forms, either unplasticized polymer or flexible plastic. An unplasticized polymer is rigid and stuff, which is very durable compared to the regular PVC that’s softer and flexible, though not as durable.
  • CPVC is a chlorinated PVC type offering unique properties, such as high glass transition temperature and heat distortion temperatures, along with chemical inertness. It has more chlorine compared to regular PVC
  • PVC-M is very tough, having a LOT of impact strength
  • PVC-O is the strongest with extremely high tensile strength

The main PVC type used for hydroponic systems is either PVC or uPVC. There is much more to think about these two kinds of PVC other than their rigidity or flexibility. For starters, these materials are typically regarded as Food-Safe, meaning it has no Bisphenol-A or Phthalates, making it safe when gardening.

You will know if the PVC material is safe if it has a mark or stamp with an NSF-51 rating, coming from the National Sanitation Foundation. These are the ones who test and set standards for public health and environmental safety.

While uPVC is regarded safe, it is still NOT recommended to use PVC or any plastics classified as type 3 for hydroponic systems. While they do have benefits, it’s better off using other alternatives.

Why?

I’ll be explaining why in the next section.

What About Regular PVC?

You might be wondering: Why not use other kinds of PVC? This is because they are not food safe. PVC is a thermoplastic polymer made from different chemicals, usually comprising of Cadmium, Lead, Organotins, and/or Phthalates. It can also give off Dioxin when burned, a dangerous chemical that’s a class 1 carcinogenic.

These are toxic to humans and will also negatively affect your plants. Furthermore, you are unable to recycle PVC pipes, and when facing exposure to sunlight for long periods, it may pass lead ash to the pipe. Over time, the PVC will leach out the toxic chemicals to your nutrient solutions, which can kill your plants or stung their growth, even if you try remedies on how to revive them.

Another disadvantage to using PVC is its difficulty in connecting them to your hydroponic system. You’ll have to glue various connections, but you risk over gluing PVC, which ends up being toxic upon installation and even risking your plant life as the glue runs through the water.

That’s why it’s important to cover your pipes with a reflective cover or paint if you plan to use uPVC for your hydroponic system. Or do keep it in a reservoir cooler.

PVC Pipe Hydroponic green and red lettuce vertical gardening
PVC Pipe Hydroponic green and red lettuce vertical gardening.

What You Should Use Instead

Now that you know not to use certain types of PVC, or to not use it altogether, what are the materials you should use for your hydroponic system?

While you can’t use type 1, 3, 6, or 7 plastics, you should be using hydro-safe plastic types 2, 4, and 5. Besides PVC, you should not use ABS pipes as well, since they contain Bisphenol A or BPA. This is known to result in various health hazards as well.

Here are our recommendations on what materials to use for your hydroponic systems:

  • High-Density Polyethylene or HDPE is referred to as number 2 plastics. These are safe to use on hydroponic systems as they won’t spread high amounts of chemicals to your solutions. It is also environment-friendly, as they are recyclable.
  • Polypropylene is plastic number 5, another safe plastic for hydroponic systems. While they are known to cause harm during their production, they are safe for your system since they would leak only a trace amount of chemicals. However, these can’t be commonly recycled.

When you use safe plastics for your hydroponic system, it would affect your plant growth and you as the gardener. Not only will your plants have better chances of successful growth, but you’ll have an easier time installing and maintaining the system without the risk of injury or intoxication.

Wrapping It Up

When it comes to building your hydroponic systems for gardening, it’s best not to use PVC. While it’s possible to use Food-Safe PVC passing standards of the NSF, other materials are actually better to use, benefiting you and your plants in the long run.

I hope that my article answered your question, ‘is PVC for hydroponics?’ Now that you know the answer, learn more about hydroponic gardening and the benefits it can offer you today.

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