Are PVC Pipes Safe For Hydroponics?

Getting to know what are the raw materials that are used to manufacture your hydroponic system is crucial for the success of any grower. Plastics are used to produce pipes and nutrient reservoirs for our hydroponic systems; this made me wonder, are PVC pipes safe for hydroponics?

So, are PVC pipes safe for hydroponics? No, PVC or plastics with type 3 are not the safest options to use for your hydroponic system. PVC plastics do leach toxins into the water present inside the container. However, there are a lot of other alternatives that can be used to avoid any negative side effects.

Whether your hydroponic system is DWC or nutrient film technique, there is a 90% chance that your system is made from PVC plastic. PVC has been around for decades. It is used to manufacture a variety of essential products from cling wraps to house piping systems.

The main issue here is that PVC might have a direct effect on your plants as a result of its unstable chemical structure that allows the release of toxins inside the water. Some people might think we can avoid the negative effects of PVC plastics as long as we flush the nutrient reservoir regularly. This is completely wrong, and I will tell you why throughout this article.

Why Is PVC Harmful For Hydroponics?

PVC plastics do contain a number of chemicals that are considered to be toxic when their levels exceed a certain point. The leaching of these chemicals happens due to a couple of reasons. Exposure to sunlight is one of the main reasons why chemicals do leach into the water.

For the do-it-yourself kind of growers, chemicals leaching will happen 90% of the time; While building your hydroponic system, a lot of growers heat the PVC pipes to mold it the way they like. Heating any PVC product makes it non-food safe because of how unstable its chemical structure has become.

The toxic chemicals are but are not limited to:

  • Lead
  • Cadmium
  • Phthalates
  • Organotins

The above toxic chemicals can lead to extreme health hazards. Let’s take phthalates as an example. High levels of phthalate can lead to severe damage to the liver and can also negatively impact the reproductive system of the human body. Another toxic chemical that is a major component of PVC plastics is vinyl chloride which is known to be extremely carcinogenic.

The problem with PVC is that over time, it slowly leaches out the above toxic chemicals into the nutrient solution. As I have mentioned before, some growers think that flushing the system on time might do the trick which is untrue.

The toxins released into the nutrient solution will somehow accumulate and increase in concentration. Flushing to some extent will help remove these chemicals every now and then, but the main problem here is that these toxins get absorbed and accumulated in the plant roots.

After the chemicals get absorbed, it enters and circulates the plant’s whole vascular system. At this point, we are already too late in stopping the leached chemicals from further affecting the plant. Even flushing cannot reduce the negative effects that these chemicals can do.

So, we have come to the conclusion that plastics with type number 3 or what is called PVC are not the best option to consider especially with hydroponics. However, there is a variety of other plastic types that are considered to be safe for hydroponic use.

The Best Plastic Types To Use With Hydroponics

The Best plastics to use with a hydroponic system are plastics with types 2, 4, and 5. These are the safest options to use because of how chemically stable they are.

Plastics are categorized into different types. These types are the following:

  • Polyester (Type 1)
  • High-Density Polyethylene (Type 2)
  • PVC (Type 3)
  • Low-Density Polyethylene (Type 4)
  • Polypropylene (Type 5)
  •  Polystyrene (Type 6)
  • Other Plastics (Type 7)

Hydroponic systems made from plastics types 1, 3, 6, and 7 are considered the most unsafe plastics to use in a system whether it is an NFT or a DWC system. They have a previous history of leaching out toxins into the water and causing a lot of medical hazards.

How To Choose The Right Plastic Hydroponic System

When you are in the process of purchasing or building a hydroponic system, you better take the right decisions. There are a lot of different aspects that you must consider during the purchase process.

Choosing The Right Plastic Type

As I have mentioned before, the plastic type of your hydroponic pipes or nutrient reservoir is crucial for the survival of your plants. Types 2, 4, and 5 are the best and safest options to use with any hydroponic system.

Try to avoid using plastics with types 1, 3, 6, and 7 as they are the most harmful types to use.

The Color Of Your Hydroponic System

I know that there are a lot of you who didn’t think that the color of their hydroponic system would matter, but it turned out to be an important part of setting the system just as choosing the right plastic type.

If you are planning to use your hydroponic system outdoors in the sunlight, then you will need to worry about which color to choose. But if you going to grow them indoors, then you are fine to choose any color that is available to you.

There are a variety of different colors available on the market, most of which are white. However, I recommend the white color for neither NFT pipes nor nutrient reservoirs for a single main reason which is the formation of biofilms.

White-colored pipes and containers tend to allow the passage of light rays when exposed to sunlight. Light rays will stimulate the growth of biofilms which can lead to boosting the spread of several infections throughout the system.

On the other hand, black-colored containers are completely the opposite. Black-coated pipes and containers will not allow the passage of light. However, black colors tend to absorb heat higher than any other color when exposed to sunlight. This could lead to increasing the temperature of the nutrient solution faster.

What I do recommend is to try and get grey-colored pipes or containers. Grey can be the perfect color to be used without needing to worry about biofilm growth or any solution overheating.

Can I Use ABS Pipes For Hydroponics?

Some people wonder if they can use ABS pipes for their hydroponic NFT systems as they are widely being used just like PVC pipes.

So, Can I use ABS Pipes For Hydroponics? Using ABS pipes for hydroponics is not safe as they contain Bisphenol A (BPA). This chemical has proved to result in a variety of health hazards that it has been banned from use in a lot of different products like baby bottles and other plastics involved in the food industry.

Abs is a stronger plastic and can withstand a tremendous amount of shocks. It is more durable than PVC which has resulted in a lot of growers wanting to use it in their hydroponic systems.

The problem is that it contains BPA which is extremely toxic and result in a wide number of health issues. This chemical has shown that it can increase the risk of cancer later in life. Moreover, studies have shown that BPA is associated with a wide range of heart diseases.



3 thoughts on “Are PVC Pipes Safe For Hydroponics?

  1. Alternatives To PVC Plastics For Hydroponics: none seemingly.

    I have looked around the internet myself and found very scarce resources for this. Perhaps it is the difficulty in finding a material that is watertight but does not corrode with the introduction of the nutrient solution to the water.

  2. Thanks for all the great info!
    One thing that I ran across when doing some research is “Schedule 40 PVC” also known as uPVC, or “Rigid PVC” that’s considered food safe by not having the plastic treated with additional, leaching plasticizers.
    I’m hoping that this could be an answer to building a RDWC system and staying clear of toxins while still being able to get piping that’s cheap and readily available from hardware stores.
    Let me know if this is something you’re aware of, or if I’m going down the wrong path.

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