Hydroponic systems are comprised of multiple components, some of which need to be suitable for food usage, such as plastics.
Are plastics safe for hydroponics? Plastics are safe for use with hydroponics if they are BPA-free and absolutely food safe. Of course, food-grade plastics that are chemical and temperature resistant are considered the best. That said, to be safe for use in a food growing system, plastics can not leach contaminants into the water supply.
Read on below and learn what’s safe and what’s not when it comes to plastics with hydroponics!
These Plastics Are Safe for Hydroponics
There are several types of plastics that are safe for hydroponics, and depending on your system it may contain one or more of them. In the following sections, we break down each type of plastic that’s safe and commonly found in hydroponics.
PVC
Our list begins with one of the most popular plastics used in hydroponics, especially for pipes and grow sites: Polyvinyl Chloride, also known as PVC.
So long as the PVC is BPA-free, the material is perfectly safe for use in growing systems. It is often chosen as a material for hydroponics because it’s strong and long-lasting.
CPVC
Chlorinated Polyvinyl Chloride, also known as CPVC, is another version of PVC. It’s worthy of mentioning here as it is markedly different than basic PVC.
CPVC is a chlorinated version of PVC and therefore tolerates fluctuating temperatures, chemical vapors, and pressure better. Like normal PVC, CPVC is often used for the water pipes and grow sites in hydroponic systems.
HDPE
High-Density Polyethylene, or plastic number 2, is also known as HDPE. It is an eco-friendly type of plastic that is easier to recycle than other plastics.
It is also highly resistant to regular wear-and-tear commonly caused to plastics by chemicals. It is a safe and suitable material to use in hydroponics.
PP
Polypropylene, also known as PP, or plastic number 5, is often considered one of the safer plastics to utilize in hydroponics. That catch is, producing the plastic causes a dangerous chemical process which is the very reason it is so safe to use once it’s manufactured. In DIY hydroponic systems, PP isn’t at all uncommon to find.
PEX
Cross-Linked Polyethylene, or PEX, is a type of plastic that is sometimes used in hydroponics but is somewhat “new” to the United States. It was created almost a century ago, as a replacement for metal pipes.
So, you guessed it, it makes a great alternative material for hydroponic pipes and grow sites. That said, not just any PEX will do. You need to check with the manufacturer to ensure it doesn’t leave harmful trace elements or foul odors in water.
PC
Polypropylene, known as PC, is one of the most common plastics used in outdoor hydroponic systems or greenhouses that utilize plastic sheets in place of glass or materials such as plexiglass.
It is perfectly safe to use in hydroponics, even for containers/grow sites.
PET
Polyethylene Terephthalate, or PET, is another of the most common plastics with hydroponics. It is the same sort of plastic that is found in soda bottles, and believe it or not, clothing.
It is normally food-grade and safe for use with hydroponics. PET is often the type of plastic used in DIY systems built with recycled plastics.
ABS
Acrylonitrile Butadiene Styrene, or ABS, is a type of plastic that most people don’t connect with hydroponics. However, it is one of the most durable types of plastics used in hydroponics.
It is also resistant to harsh chemicals that may cause other plastics to break down. The fact that it is more expensive than other plastics on this list is more than likely the reason we don’t find it in more hydroponic systems.
Avoid Using These Plastics With Hydroponics
There are also several types of plastics to avoid using with hydroponics. Just remember, even if the plastic is typically considered safe, if it isn’t BPA-Free, and is food-grade, it isn’t fit for use in a hydroponic system that produces food.
The main plastics to avoid for hydroponics include:
Plastic #1
This sort of plastic is unfit for use in hydroponics after it has been exposed to heat or harmful chemicals. It is also unfit if it wasn’t food-grade to begin with. Otherwise, in some cases, this plastic may technically be safe enough for hydroponics.
Plastic #3
Number 3 plastics belong to the Polyvinyl Chloride, just not the BPA-free and totally food-safe type. These are the plastic bottles that are manufactured for cleaners, shampoo, and other products.
Avoid using them for anything to do with growing food, they are not safe.
Plastic #6
Plastics of this sort are not fit for use in growing systems. They are most commonly found in items like plastic cutlery, laundry powder scoops, and measuring cups.
These plastics are also found in materials like foam. Don’t attempt to use them in a hydroponics system, they may be toxic.
Plastic #7
The last plastics on our list of what to avoid is LEXAN, and any other PC or plastic number 7 that isn’t BPA-free and food safe. These are found in car parts, baby bottles, water coolers, and more. Never use them for hydroponics.
Is PVC Safe for Hydroponics?
Whether or not PVC plastic is safe for hydroponics depends on the type and grade of PVC that is in question. The only types of PVC plastics which are absolutely safe for hydroponics are 100-percent food safe and BPA-Free.
Is CPVC Safe for Hydroponics?
The chlorinated version of PVC, also known as CPVC, is safe for hydroponics in addition to being far more resistant to chemicals, temperatures, and age than normal PVC. That said, it must be food grade or it isn’t fit for use in a hydroponic growing system.
Can You Use Old Food Containers for Hydroponics?
Old food containers are one of the most common types of recycled containers found in at-home DIY hydroponic systems. These range from plastic water bottles and milk jugs to glass mason jars and plastic ice cream containers.
Can You Use Recycled Plastics for Hydroponics?
Recycled plastics can be safe for hydroponics, but you must know what type of plastics they are. For example, recycled plastic numbers 1, 3, 6, and 7 should be avoided completely, while plastic numbers 2, 4, and 5 are perfectly reasonable to use.
Can You Use Glass for Hydroponics?
Glass may certainly be used for hydroponics, though it is not the most economical of materials to use in bulk. That said, DIY mason jar hydroponics is an extremely good example of how glass may be useful in hydroponics at an affordable price point (or even for free).
Do Hydroponic Buckets Need To Be Food Grade?
Any material that’s used in a hydroponic growing system needs to be food grade, period. Otherwise, there is a chance that chemicals could leach out from the pipes, into the water, and contaminate the plants and their produce. Non-food-grade pipes may also cause bacterial build-ups that end up in the water supply as well.
Are There Alternatives to Plastic for Hydroponics?
There is always another way, even in hydroponics. When it comes to using plastics with hydroponics, it is the best and easiest path. But, it is not the only one.
The lightweight metals found in gutters, roofing, and siding may be a feasible option, as are natural materials like bamboo. The cost of said materials, and finding components to work with them, is hit or moss
What Are Net Pots Made Of?
Net pots are the containers that sit down inside of hydroponic systems grow sites. For the most part, these pots are made of high-quality virgin plastics. However, this is not always the case.
That’s why you need to double-check what sort of plastics any netted pots are made of that you’re considering using in your growing system.
Can I Make My Own Net Pots?
Making your own net pots is a very realistic option. All you need is a few simple tools and a few recycled plastic containers. Soda bottles, plastic cups, and yogurt cups make the quickest and easiest DIY net pots. Just use a knife, nail, or drill bit to make enough holes. Check some netted pots for sale online for examples.
A Final Word About Hydroponics and Plastics
The bottom line is that there are several types of plastics that are used with hydroponics, and as long as their BPA-free, and totally food grade, they are safe for use in your hydroponic system.
PVC is highly recommended because of its low cost and high availability in comparison to other less affordable plastics.
That said, PP, PC, PE, ABS, and PEX can all be used with hydroponics as well.