What Is Osmosis in Cannabis Plants and How It Works

What is Reverse Osmosis Water? Using Reverse Osmosis Water in Cannabis Cultivation. How to Grow Cannabis With Reverse Osmosis Water

Maximize Your Marijuana’s Potential With Reverse Osmosis Water

Do you understand everything about growing high-quality marijuana buds? We’re sure you already know about using a suitable grow medium, the best nutrients, and giving your crops enough light. But are you aware that reverse osmosis water is a cannabis plant’s preferred drink?

Even easy seeds to grow may develop health problems if the H2O you give them contains too many impurities. The excess calcium, chlorine, and fluoride sometimes found in tap water affect marijuana plants’ growth and nutrient absorption.

Giving your plants reverse osmosis water is a simple way to keep them happy and healthy. Keep reading to discover what this liquid is and how it can increase your yields.   

What Is Reverse Osmosis Water?

When growing cannabis, reverse osmosis is important if your tap water contains too many dissolved salts or microbes. These contaminants can lead to nutrient lock-out or diseases such as root rot.

Reverse osmosis produces some of the cleanest H2O around. High pressure forces the liquid through specialized filters that remove foreign bodies, including salt and bacteria. The purified water drains through, while the impurities stay behind. 

This process removes around 95–99% of the contaminants found in tap water, resulting in almost pure H2O. 

Using Reverse Osmosis Water in Cannabis Cultivation

Should you give your plants reverse osmosis water? Every gardener has different challenges to overcome when cultivating marijuana. Read on for the pros and cons of using reverse osmosis to decide if your crops can benefit from it.


Reverse osmosis is one of the best forms of H2O purification available to cannabis growers. The reasons to consider using it in your garden include:

Feed Your Plants With Greater Accuracy

Municipal tap water doesn’t contain a consistent amount of minerals and gets treated with chemicals like chlorine. This H2O source needs careful testing before adding nutrients to ensure you’re not damaging your plants.

When growing cannabis with reverse osmosis water, your feeding becomes fine-tuned. Starting with almost-pure H2O means supplying your crops with the exact food they need. This precision prevents supplement shortages or excesses and results in optimal plant development.

Useful in All Grow Setups

Reverse osmosis water is suitable for any grow setup. While it improves health and increases yields of soil-grown marijuana, it truly shines when using hydroponics in cannabis cultivation

In this type of garden, high-quality H2O is vital as it carries and transfers nutrients to the plant roots. Using H2O with incorrect chemistry starves marijuana and may damage the hydroponic system.

Using reverse osmosis for cannabis growth also lets you cultivate the plant in any area. If you live in a region with unsuitable tap water, this system removes the impurities. The purified H2O is safe and boosts plant growth.

Easy to Get

It’s easy to get your hands on some of this pure liquid goodness. Many cities have stations where you can purchase reverse osmosis water in refillable jugs. 

If going out for supplies is too much hassle, invest in an at-home unit. Basic and customized reverse osmosis cannabis watering systems are available online. They range in price and integrate easily into your existing household plumbing. 

The pressure mechanism is simple and doesn’t need much maintenance. You need to change your filters every few years, depending on your tap water contamination levels and daily usage. 

As a bonus, this filtered H2O tastes great and is healthy for people to drink.


Is reverse osmosis recommended for growing cannabis? Yes, it’s a fantastic way to improve overall plant health; however, there are some disadvantages to be aware of.

Water Waste

The average reverse osmosis system uses around four gallons of H2O for every one gallon it filters. Some units use up to 20 gallons to purify just one. This wastage is a significant issue, especially if you’re in a water-restricted area or concerned about high utility bills.

New machinery is emerging that reintegrates the waste into household plumbing, making the system 100% efficient. These zero-waste machines will eventually become a standard in reverse osmosis filtration. 

Plumbing Damage    

Growing your cannabis using reverse osmosis water could be detrimental to your copper pipes. As this pure H2O doesn’t contain minerals, it may corrode metals.

Ensure all plumbing is rated to withstand reverse osmosis water to prevent future repairs. 

How to Grow Cannabis With Reverse Osmosis Water    

There’s not much difference between hydrating your marijuana with tap or reverse osmosis H2O. You just have to add a few supplements to the pure water before giving it to your plants.

Make sure the pH is suitable before mixing in nutrients. Soil-grown cannabis grows best in a range of 6.0–7.0, while 5.5–6.5 is best for hydroponics. Easily adjust any incorrect levels with a pH balancing kit.

Calcium and magnesium are essential for photosynthesis and must be put back into reverse osmosis water meant for plants. Check the instructions of the supplements you’re using to be sure you’re adding the correct amounts.

Once you’ve balanced pH, calcium, and magnesium levels, add any other nutrients as you usually would. If you’re concerned about overfeeding your marijuana plants, alternate giving them tap and reverse osmosis H2O. 

Maximize Your Marijuana’s Potential With Reverse Osmosis Water 

It’s not essential to give reverse osmosis water to your cannabis plants. Marijuana can grow and develop decent yields with tap H2O, as long as it’s clean.

If you want precise nutrition and the elimination of impurities, reverse osmosis is for you. It gives you a base from which you can perfect your mineral and pH balances and take your cannabis growing to the next level. 

Cortney Bennett

Cortney Bennett, a pharmacist at I49 Seed Bank, with 5+ years in the pharmacy field regarding cannabis. Cortney constantly upgrades her knowledge and skills in the weed industry. She has learned the characteristics of the different marijuana types and their effects on the human body in detail. Her constant thirst for knowledge allows her to stay up to date with all the latest research and discoveries in the cannabis field.

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