If you have a green thumb but limited space, hydroponics is the perfect way to plant crops in your home. With hydroponics, farmers skip the soil and plant their seedlings in plastic containers of nutrient-rich solutions with access to water and light.
This compact, inexpensive, and space-saving setup provides you with fresh plants, herbs, and produce even if you don’t have a yard or garden.
When building your hydroponic garden, there are several crucial factors to keep in mind, the most important of which is what material to use for construction. You will need to set up pipes to carry clean water to your plants.
Some publications recommend using PVC for your piping, but you might have questions about its suitability. Is PVC safe for hydroponics? Let’s find out.
You should also read: What Is The Best Hydroponics System For Beginners?
PVC Composition and Types
PVC (polyvinyl chloride) is one of the world’s most produced synthetic polymers. It is a very stable compound made of natural gas and rock salt that undergo various processes, from heating to melting and shaping into pipes.
The polymer has a host of beneficial properties that can go a long way in determining the success of your hydroponic setup. However, not all PVC pipes are created equal.
There are five main types of PVC pipe you can find at your local home improvement store:
- PVC-P: Also known as plasticized PVC, this type of PVC has phthalates and Bisphenol-A. It is also flexible because of the plasticizers it contains.
- PVC-U: This type of PVC is unplasticized. While this property makes them the safest choice, it also prevents them from being as flexible as PVC-P.
- PVC-HI: This is an industrial-grade type of PVC that blends well with various polymers to create the most durable and resistant PVC.
- C-PVC: Mostly used for residential drinking water, chlorinated PVC is more stable, has greater flexibility and heat resistance, and higher chlorine content.
- PVC-O: This is an enhanced version of PVC-U. Molecularly Oriented PVC has a much higher resistance.
Benefits of PVC in Hydroponics
It Is Cheap
When compared to plastic or metal pipes, PVC pipes are very affordable. Its low price allows many homeowners to set up their hydroponics systems at a minimal expense.
It Is Efficient
PVC is not as toxic or soluble as other materials. Furthermore, it is flexible, lighter, and more durable than some of the other materials you can use to set up your hydroponic garden.
You Can Use It Indoors or Outdoors
The PVC pipes will perform very well regardless of the weather – a quality that many materials do not have.
Some materials cannot withstand certain weather conditions without cracking or breaking. Furthermore, were you to set up your system indoors, the PVC pipes would perform even better.
It Offers Multiple Configurations
There are multiple sizes of PVC fitting that you can get. On top of that, they are available in various lengths, thicknesses, and rigidities. The availability of such options means that you can design and customize your hydroponic pipe system however you want to.
It Is Durable
When you keep them under the right conditions, your PVC pipes will last a long time and serve you and your plants well. The pipes can handle stress and sudden pressure, staying a long time without needing replacements.
Which PVC Types Are Best for Hydroponics?
Most hydroponics use C-PVC and PVC-U because of their wide availability and safe properties.
For instance, C-PVC is inherently inert, meaning it is resistant to most acids, bases, and salts. Its resistance makes it a suitable option for transporting hydroponic nutrient solutions.
Also, both PVC-U and C-PVC have been tested by different standards organizations, including the:
- US EPA
- American National Standards Institute
- NSF International
- ASTM International
- American Water Works Association
Furthermore, since PVC-U and C-PVC are unplasticized, they fall under Recycle Number #3 – food-safe plastics.
Differentiating between the Two
You can easily differentiate between C-PVC and PVC-U by looking at the manufacturer’s markings printed in black at the end of the pipes. You should look for markings such as NSF-61, Schedule 40, and NSF-PW because these are safe for hydroponics and aquaponics.
Where Does the PVC Confusion Come From?
There are various reasons why you might come across other hydroponics enthusiasts asking, “Is PVC safe for hydroponics?”
The internet contains conflicting information about PVC. First, most of these conflicting reports stem from the lack of differentiating between the various types of PVC.
Flexible PVC contains plasticizers that have phthalates and BPA. Using such types of PVC pipes in your hydroponic system could result in your plants absorbing these chemicals, which studies have shown can be harmful to plants and humans.
Not to worry: since rigid PVC does not have plasticizers, it is free of BPA and phthalates.
Ensuring the Safety of Your Hydroponics
While rigid PVC lacks several harmful chemicals, it still contains a few that could be toxic when levels surpass a specific point. The pipes could contaminate your garden with chemicals like:
- Cadmium
- Lead
- Organotins
These toxins can lead to several health hazards, especially if they accumulate and increase in concentration. Though there are various reasons why these chemicals could leach from PVC pipes, exposure to sunlight and extreme temperatures are the main ones.
To prevent your PVC pipes from deteriorating and releasing harmful chemicals, protect them by painting them. On top of that, ensure that you continuously circulate water in your hydroponics system to keep the operating temperature well below the 140°F limit.
In Summary
Yes, PVC is safe for hydroponics, depending on the type of PVC you use. Because of their low cost and availability to their efficiency and durability, PVC pipes can offer you several advantages.
However, while PVC can be safe for hydroponics when used correctly, it is not the best plastic to use. There are other, safer plastic options that you could consider using, including:
- Polyester
- Polypropylene
- High-density polyethylene
- Low-density polyethylene
These plastics are considered the best options to use for your hydroponics because of their chemical stability — they will not leach chemicals the way PVC pipes will. This advantage could benefit you and your crops in the long run.