Reverse Osmosis- RO Water For Plants

Reverse Osmosis- RO Water For Plants

Reverse Osmosis communally abbreviated as RO water is super beneficial to any horticultural garden. Have you ever had a deficiency and was complete stupefied why you could not fix the problem? Is having 100% control over over your nutrients and plants important to you? Do you have a Well or high levels of total water hardness? Are you using a water softener to reduce your total dissolved salts (TDS)? If yes to any of these questions you ultimately should invest in a RO water system. I am here to help you understand how they work, the benefits and how to pick the right RO system.

Benefits of RO water

The benefits of RO water is practicality: it gives you greatest control over all the nutrients your plants receive. Doesn’t sound just like pH when you phrase it that way! Just as important it will allow you to use a water source that is particularly not plant friendly.  I personally use a RO water system so I can contest to the benefits.

An RO water system will convert your TDS down to almost zero ppm. Your water is than eliminated of all trace elements leaving you with a unbalanced pH level- more about that later. The benefit with all trace elements removed now leaves you complete control over what your plants feed is.

For example: lets assume you are following a nutrient feed program and once you apply all your nutrients according to the chart your water ppm will raise- this will be according to your nutrient strengths. In reality if you have not used an RO water system, your PPM will be greater than your nutrient feed program expectations. This is because when measuring your ppm you are actually measuring your normal tap water TDS as well as your nutrient feed salts. As a result, your over all nutrient strength greater than anticipated.

Typical tap water- so annoying.

Normal tap water contains all forms of trace elements that may interact with your nutrient program. The trace elements may contain ratios that will combine negatively with your molecular bonds of nutrient; in which, you may be locking out some important trace elements. But more so, your confused because your giving your plants an excellent high quality fertilizer! And still are having problems, read on.

Tap water ether from a Well or City is unpredictable and curated for human consumption. Well water usually contains high levels of calcium and magnesium. In combination, your total alkalinity or hardness will increase. The complexity behind high levels of harness creates issues of pH balancing as well as nutrients that are not plant available. The molecular structure is to large to be permeable.

8 Common Metals Found In Your Water

Typical Well water can range from 200-600ppms. Typical elements are listed in alphabetical order and not by priority!

Aluminum –  Aluminum is extremely common within the earth but usually not in high concentrations in Well water. Aluminum can pose negative effects on humans and plants by interrupting cell formation. RO water will reduce aluminum toxicity.

Arsenic – Arsenic is very common in Well’s near farms since its common in pesticides. Water tables change over time and may test negative one year but positive the next. Arsenic is not required by plants but can be toxic simply by playing havoc on your bacterial within your soil.

Calcium – Calcium is a metal that both plants and humans require. If calcium levels are high what is the hardness? High levels of calcium can accumulate in soil and reduce the uptake of other nutrients such as phosphorus, potassium, magnesium, boron, copper, iron, or zinc, resulting in deficiencies of these nutrients. High levels of calcium will cause issues to your hydroponic equipment, typically drip systems.

Copper – Large dosages of copper affects all plants differently but can create major issues when rooting/cloning or transplanting.

Iron – Iron creates havoc on your hydroponic equipment as well as your soil. Iron can be a potentially source for pathogenic organisms. For cannabis growers, lower pH levels will result in more iron availability to your plant which could result in plant burns and root damage.

Lead – Lead is a poison and createsnmany issues with plant health. Lead is a cancer to plants and any water with lead should not be consumed or feed to your plants. Lead will destroy ATP production and seed germination.

Magnesium – To much magnesium is very rare for plants but little is actually known how Mg toxicity effects them. The best consensus is the inability for proper plant signaling with regards to stress, ATP and chlorophyll productions. Ideally, magnesium is beneficial to your plants if found in water.

Sodium – Sodium is considered not required by plants. Only some require sodium for carbon dioxide synthesis. Plants require very little for plant metabolism. Sodium can easily accumulate within your soil resulting in toxic or nutrient burn. Plants can become dehydrated much like humans do when we drink ocean water; this is the function of osmotic effect of salinity. The word osmotion is not correct and uselessly used by hobbyist. An RO system is a must if using a water softener as sodium salt is used to exchange the TDS of the water.

The common metals listed above are listed in alphabetical order, not by relevance. Since relevance is particular to Geo locations, I would argue most common water problems that effect people and their plants are: calcium, magnesium, iron and sodium. Also, chlorine and chloramines should be considered unnecessary for cannabis plants.

Chlorine & Chloramine

Chlorine and chloramines are used to disinfect common drinking water. The chlorine levels vary from municipality and precautions should be taken. Chlorine in particular, kills bacteria and all micro organism in soils. These are the organism that are beneficial to plants and help facilitate nutrients to a plant available form.  To be fair, chlorine levels are generally low and a cannabis plant cycle is short; therefor, the effects would be minimal especially for the synthetic nutrient gardener. A synthetic product already dehydrates the benefical bacteria, must like salt on a leach!

Chlorine + Chloramine Precautions.

Prime water condition for chlorine

Easy precautions can be taken to reduce chlorine levels: You can use a product called PRIME which helps remove chlorine and chloramines. The product is used within salt water systems and considered REEF SAFE. You can also agitated your water for 24-48 hours before giving to your plants; this will not remove chloramines.


How does RO systems work?

The proccess is slow but simple. High concentrated water gets pushed through a semi-permeable membrane by a force; pressure by a pump, city supply or pressure tank. The result is two byproducts created. One byproduct is the extremely low concentrated water and the other is the salts/metals left rejected and flushed down the drain.  Below is an image on how a typical filter system works. They can be installed in several retrofitted ways.


RO systems explained by healthy cannabis reviews

Is RO water environmentally friendly?

The major set back with a RO water system is that they are not environmentally friendly. They do require a drain to waste approach. The drain-to-waste approach is characterized by ratios of 2:1 or 1:1 RO water production. For example: a ratio of 2:1 is a faster RO filter system by which you will create more waste water. To create 1 gallon of drinking water, you require 2 gallons of waste water; therefore you must plumb a drain line into your drain waste system.  The main difference between a 2:1 or 1:1 ratio is the tubing size, large the tube, the more water can flow.

The typical filtration cycle for most RO water starts with a basic 3-stage filter. The 3 stages are, mechanical, chemical and than your RO membrane. You can get very expensive RO systems that allow for multi stage filtering, this all depends on your filtering needs. The mechanical will remove the settlements such as sand or debris. Chemical filtering is typically a charcoal to help remove basic metals that are large and heavy. And the RO membrane is the real work horse, she is designed to remove all TDS.

Do not get confused with purity

An RO water system should not be confused with water purity system. Most advertisement claim ttheir RO water system purify water-this is not true and only marketing. Its a damn crime. Purity is based on the safety of your drinking water. Do you have harmful organism which than you would need a RO/DI system. Typical RO water systems do not remove Total Coliforms. Colifrms are microbes that are usually tested when purchasing a home with a water Wells. These test usually range around $225 CAD.

Fecal Coliforms are a type of Colifrom that is from human or animal stool. E.coli is part of the fecal Colifrom group. These germs can make you very sick and is not removed by a traditional RO system. In fact, you must use your RO system regularly to reduce build up of potential bacteria within your filters! You must flush your unit monthly and replace the cartridges based on heavy use or yearly maintenance.

Are you using a water softener?

Water softeners are extremely popular for treating hard water. But what most people do not understand is how they operate. Water softeners actually is an exchange program between hard metals, from tap water, to sodium salts that your water softeners requires. For example: If you have 600PPM of TDS entering your water softener, you will have approx 600PPM of sodium for the exchange. You will still be feeding your plants 600PPM of sodium! How do you fix this? You must get an RO water filter.

Water Softener First THAN RO System Second!

Feeding your plants that much sodium is unacceptable and requires a RO systems. An RO membrane is very sensitive and will become inefficient with heavy use. The RO membrane should be protect and most RO system void warranty if using with well water over 300PPM.

The RO system can remove sodium ions much easier than heavy metals. This is why the best combination for your garden is a water softener and RO system. I understand this can be expensive. IF you can only afford one unit, purchase a RO system. Water softeners are generally around $800-$1000 CAD and may require a plumber if your not comfortable with drain waste connections. If your using city tap water, a RO water system alone is adequate.

What RO size do I buy?

That is a very easy answer, you buy the biggest RO system you can afford. RO water systems are not efficient and producing a lot of RO water takes time. A common RO system for under the sink is typically 50gallons a day, which comes with mini pressure tank and 3-5 gallon storage system.

A cannabis garden is much more demanding and may require 50+ gallons a day. In this case you will be required to purchase a minimal of 150gallon RO water system.  RO water systems are based on several key features such as, water pressure, TDS and temperature for greatest productivity. For marketing reason RO manufactures list the MAX output if all key features are met but they do not tell you that.

For Example: If your RO water temperature efficiency rating at 22.5degrees Celsius, than to reach 150gallon per day output you are required to have 22.5degree water as your input. If you are pulling from a Well with ground water temperatures ranging from 5 degrees in the winter to 15 degrees in summer, your total efficiency rating will decrease dramatically. Your net RO volume may be as low as 20 gallons per day! I’m not asking you to trust me with much but understand I learned this from personal experience.

Which RO System? Hydro-logic Stealth-RO150

In our community, the hydro-logic system is the most commonly bought because its priced right, reliable and simple enough for the first time buyer! The hydro-logic stealth system is small enough for most places but offers an 2:1 or 1:1 ratio. You can read more about the HYDROLOGIC Stealth-RO150 for further research.Personally, I use this product as well as, every other grower I know. We have zero complaints and this unit allows most rural growers to use the local water sources.

How To Balance RO pH

Balancing RO water is difficult at first and probably the biggest draw back. You must add CalMag product to help balance the water chemistry before adding your 2-3 part feed program. The CalMag will add approx 200ppm to your water if using 1ML per 1L for a 5 gallon bucket.  The 200ppm will help balance the RO water pH and reduce the pH swings when mixing.

Your second option is to partially mix new RO water with non filtered water. This is much more tricky and possibly a bad idea. I do not recommended this approach. You do not know what is in your water to begin with. Even if you tested your water, it was not a FULL water analysis therefore, you do not know the ammonia, nitrites or nitrates as well as the concentration of each particular metal. Just keep it simple and purchase the CalMag. One bottle should last most hobby growers a cycle.

Final Thought

Okay, now you have the scope of what is an RO system and how does an RO system work. I hope you understand the main goal for the RO system; it is to remove metals and reduce all TDS; for which, you can now have complete control over your nutrients. Furthermore, I hope you consider the purchase of an RO system and remember it is not used to purify water! If purification is required, consider a RO/DI system. If you found this article interesting, don’t forget to leave a like on our Facebook page and comment below 🙂

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This Post Has 3 Comments

    1. Hey
      I appreciate your comments..When I switched over to RO water for my garden I could not find a site with specific details, how it works, how its installed and which one should I buy? I would find info from popular websites that was really almost copy written from another site and so forth.. Really annoying. And after a long talk with my hydroponic store and several customers inline I found that RO water was highly miss understood.

      Feel free to subscribe to our email list as your will get each new post sent to your email as well as, various seed offers and services not publicly listed.
      Thank you once again.

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