7 Best Reverse Osmosis Systems For Hydroponics [2022 Reviews]

Not all water is created equal, and when it comes to hydroponics, ensuring your water is chemical-free means healthier plants. How do you ensure the water you are using is free of impurities that may damage your plants? A water test is one way, another is to use a filter on your water. There are many water filtration systems out there, but the top-of-the-line system is Reverse Osmosis.

How Does Reverse Osmosis Work

This is where it gets a bit technical, but that is because the reverse osmosis technique is so efficient at eliminating byproducts from water. A high-pressure pump increases the pressure on the ‘salt’ side of the Reverse Osmosis and forces water across the semi-permeable Reverse Osmosis Membrane. This process eliminates around 95-99% of dissolved salts, and the product water is now deionized, free of impurities.

The contaminants that didn’t pass through the Reverse Osmosis membrane are called the concentrate (or reject) stream. The reject stream can either be recycled back through the Reverse Osmosis System or go to the drain system. Most Reverse Osmosis Systems remove between 95%-99% of contaminants, by-products, and chemicals from tap water. 

The main difference between Reverse Osmosis Systems and standard filters is that Reverse Osmosis Systems utilize cross filtration, whereas standard filters just collect the by-products. Cross filtration is basically two filters- the filtered water goes one direction and the contaminated water goes the opposite direction. This ensures the unwanted materials are swept away from your water supply.

Why Reverse Osmosis For Hydroponics

Because hydroponic growing relies heavily on water instead of soil for nutrition, having pure water helps ensure healthy and strong plants. Reverse Osmosis systems can be put on your home’s main water supply, and you can use it for a variety of purposes, making it a worthy investment. Other solutions are to install it at the main sink where it will be used. Whether in your kitchen, mudroom, or backyard, the Reverse Osmosis Systems below can be easily installed at any sink.

[1] iSpring RCC7 Reverse Osmosis


  • NSF Certified, under-the-sink mounted water filter
  • 5-stage process that removes up to 99% of contaminants, including lead, chlorine, fluoride, arsenic, asbestos, calcium, sodium, and more
  • Easy installation, telephone support offered
  • Premium quality components, manufactured in the USA with lifetime support offered

All systems from iSpring go through intense testing for air leaks, cycle, and pressure resistance to maintain quality and high performance. If you do run into a problem with this system, whether during installation or otherwise, the company is there to answer and support you.

We like how the 1st-stage housing is see-through, which makes checking your filter quick and easy. The high-throughput RCC7 membrane is rated for up to 75 gallons per day, which means you will have plenty of pure water for your home and plants.

[2] APEC Water Systems 5-Stage Reverse Osmosis Drinking Water Filtration System


  • 5-Stage Reverse Osmosis System
  • Engineered and assembled in the USA
  • WQA Certified System
  • Premium long-lasting filters
  • Noise-free system
  • High-quality leak-free quick connect fittings

This Osmosis System comes with a 100% lead-free designer faucet, plus Certified JG Food grade tubing and parts to provide safe, contamination-free water. The company offers a 2-year extended manufacturer warranty with registration, and videos are included for easy installation. APEC has 20 years of experience making heavy-duty, trouble-free, and clog-free Reverse Osmosis Systems.

[3] Waterdrop RO Reverse Osmosis Water Filtration System


  • Composite filters and tankless design
  • The 3 filters, which are included, provide 7 stages of filtration
  • NSF Certified Performance
  • Installation in minutes, the filter can be changed with one single turn
  • The internal pump offers water flow at 400 Gallons per day

Waterdrop has made the first tankless and smart Reverse Osmosis System to hit the market in the USA. The tankless design helps you enjoy more storage under your sink. The low drain ratio of 1:1 means that this system saves wastewater by 300%.

It seems that with this system you can save money on your water bill while being eco-friendly, too! A special note is to flush the Reverse Osmosis system for 30 minutes after installation, and well water is not recommended. 

[4] Home Master Undersink Reverse Osmosis Water Filtration System


  • Innovative design solves most common problems associated with canister & tankless systems
  • Patented remineralization systems adds calcium and magnesium twice during the purification process
  • 7 stages of filtration, no electricity required
  • Faster flow rate with tubing and fittings twice the size of other systems
  • NSF Certified Components and NSF listed company
  • Made in the USA, BPA and lead-free

Although the price is on the higher end, this reverse osmosis system has many different features that explain why. A 5-year limited warranty is given on the system, which is built with a modular design so it is easy to upgrade and service. Filter changes are once per year or 2000 gallons, no wrenches required.

The Home Master catalytic carbon outperforms standard activated carbon in removing chemicals. It also has a dedicated sediment filter which prolongs the life of the other filters, ensuring the highest possible water pressure.

[5] APEC Water Systems 6-Stage Reverse Osmosis Drinking Water Filtration System


  • Designed, engineer, & assembled in the USA
  • 6-stage system with 75 Gallons Per Day
  • Feed Water Pressure 40-85 psi
  • The USA made cartridge uses food-grade calcium from a trusted source
  • WQA Certified, 2 year extended manufacturer warranty with registration
  • 4 Gallon pre-pressurized water storage tank

APEC Water Systems has been making Reverse Osmosis systems for 20 years and guarantees a trouble-free, noise-free system for long-lasting pure water. The filters are premium and long-lasting, able to treat tap and well water. The system comes with a lead-free designer faucet that is high quality and leak-free. If you’re looking for a dependable system, this APEC system might be the one.

[6] NU Aqua Platinum Series 7 Stage Reverse Osmosis System


  • Alkaline and UV Ultraviolet
  • 6-stage systems to provide the cleanest drinking water possible from home
  • NSF approved Reverse Osmosis storage tank
  • 100 Gallons Per Day, Booster Pump
  •  HydraCoil™ Technology provides superior water filtration

One of the many cool features of this system is it comes with a reverse osmosis faucet, and once it is opened, water stored in the NSF-approved pressure tank is drawn through an inline T33 granular activated coconut shell carbon filter, which polishes your water for a clear taste. The HydraCoill™ technology allows for 50% cleaner water than other comparable systems.

Adding a UV bulb sterilizes water before it reaches the faucet, killing 99% of bacteria and viruses. If you’re not satisfied within 180 days, the company will issue a full refund. This Reverse Osmosis system comes with a lot of bells and whistles, but for the purest water, may be well worth it.

[7] NU Aqua Efficiency Series Tankless


  • 4-stage tankless filtration system
  • 600 Gallons of Water Per Day with a 2:1 pure to waste ratio
  • Easy installation, compact design takes up little space
  • Easy to install filters that are tool-free and twist-lock 
  • Smart faucet changes color when a new filter needed

It feels like NU Aqua has thought of it all with the tankless Reverse Osmosis System. It also has an integrated booster pump that not only increases efficiency but also allows systems to work with low water pressure. Its sleek design can fit in almost half of the space a standard Reverse Osmosis system takes up, perfect if you are limited on space.

What makes NU Aqua products stand out from the rest is their HydraCoil™ Technology, which they say provides superior water filtration performance by removing over 230 chemicals and contaminants from your tap water.

best reverse osmosis system for hydroponics


What Contaminants Are Removed in Reverse Osmosis?

Reverse Osmosis Systems use technology that removes up to 99% of contaminants, such as chlorine, toxic fluoride, arsenic, aluminum, lead, nitrates, heavy metals, 1000+contaminants, taste, odor, and VOCs. When a reverse osmosis system contains UV light, viruses and bacteria are also removed as the water is sterilized from the UV light.

What is a Good ppm For Reverse Osmosis Water?

A good ppm (parts per million) is below 50, which is what reverse osmosis systems can achieve. TDS (total dissolved solids) levels around 150 ppm are generally sufficient.

What is the pH of Reverse Osmosis Water?

Reverse Osmosis water is slightly more acidic than regular water. Regular water has a pH level of around 7, and Reverse Osmosis pH levels are between 6-6.5. pH can be tested using a pH meter for hydroponics.

Is Reverse Osmosis Healthy For Me Too?

Absolutely! By filtering out all the toxic chemicals, only pure water is left to nourish your body, just as nature intended it to. Some people worry that too many minerals are extracted; here you need to just weigh the pros vs. the cons, and for us, removing the contaminants seems worth it.

Nah, I think water is just water. Do I really need to use Reverse Osmosis in hydroponics?

Besides the health benefits for you, one of the most common practices in hydroponics is to use Reverse Osmosis water to create nutrient solutions for your hydroponic plant babies. If your tap water contains minerals or substances that can cause significant problems with your hydroponic plants (such as sodium, fluorides, and carbonates), then it is worth it to use a Reverse Osmosis System to remove those substances.

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