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Benefits of Using Reverse Osmosis Water in Hydroponics & Organics

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The debate around the quality of the water we use on our plants and garden is literally a simple one. Some say that if the tap water in your home is good enough for us to drink, then it is surely good enough for our gardens.
Not necessarily so, you have to remember some countries around the world have a bad quality of tap water. Sometimes the water is so bad, that it is literally undrinkable. Think the amount of times on your travels around the world, the amount of times you may have you heard the phrase “don’t drink the tap water”! Unfortunately this is the case in the UK in some regions.
Thankfully here in the UK we do actually have one of the best water work systems in the world. But even here in some of the different parts of England the quality will differ. Hard water is water with generally a high mineral content opposed to soft water. 



By observing the map above you can clearly see that 60-70% of England’s drinking water is actually in hard to very hard water areas. Gardeners residing in the blue areas of the map, will more than likely not need a filter or osmosis system. Those of you who live in the yellow areas of the map will most probably need a water filtering mechanism. But no matter where you live within the UK whether it be in the blue or yellow areas I would still check your water quality. You can do this by having an EC meter that most good quality gardening stores provide. An EC meter is short for electrical conductivity meter. It can measure the electrical conductivity in a solution. Used in hydroponics, aquaculture, aquaponics and freshwater systems to monitor the quantity of nutrients, salts or contamination in your water.
London especially suffers with a hard water problem, our water is laden with contaminants within the water, ranging from elements such as calcium, magnesium and sodium but the harder your waters alkaline then more of these compounds of iron, potassium, sulphur, nitrates and trace elements such as boron, copper, manganese and zinc will be found. But ultimately the goal here is to have your water read at zero. Only then will your chosen nutrients show you what they are really capable of producing for you. An excellent reason to invest in a filtering system, as without one you really can’t tell what you’re feeding your plants. Remember that RO water basically gives you a clean slate to start with, thus allowing you total control and 100% knowledge of what you’re feeding. Ultimately the majority of growers who do convert to RO water agree that the introduction of RO water significantly increases your overall quality in your end produce.
If you are not sure test your water and if you have a starting EC in the range of 0.2 to 0.8, or higher it means you have unwanted and unknown elements within it, thus, the balanced elements in your nutrients can become unbalanced when added to unchecked and unfiltered tap water. This can cause deficiencies or even a nutrient lock-out, which can have devastating effects on the general health of your plants right up to the rate in which your garden grows.
Reverse osmosis water and filtered water is the peace of mind you really can buy...By investing in a RO machine it will provide you with a consistent stock of clean water. By taking away the alkalinity from your water it will also you to help to prevent clogging up of mineral salts, in your irrigation pipes, drippers or sprinklers. This allows your systems to run blockage free and alleviate the need to add any cleaning agents for your reservoir. Another good reason to use RO water or purified water is if you use a humidifier in your grow room. As normal tap water in a humidifier will eventually clog up of your machine and will also stop it from spraying a kind of whitish residue which unless wiped down after every grow, will deteriorate the longevity of your grow room equipment from your reflectors not being able to reflect properly to a carbon filter or grow light under performing. By using RO water in your humidifier, it will help shave down your cleaning regime.
Another very good reason to convert to RO or purified water is especially for organic growers who use organic nutrients and organic additives. Especially gardeners, who bother to brew their own compost tea, will undoubtedly find that filtered water produces better results and quality. This is mainly due to tap water containing chlorine which is a cleansing agent. It comes in either the form of chlorine or combined with ammonia to form chloramine. It is commonly known that allowing tap water to sit for around 24 hours allows the chlorine to slowly evaporate off. This time can be reduced to an hour if you aerate your water and simply bubble it. Unfortunately this is not the case with chloramines. Chloramine takes much longer to evaporate and would actually take several months to completely evaporate. Therefore organic growers understand the necessity of RO water, especially those organic gardeners who add beneficial bacteria and micro-organisms, such as Trichoderma and Mycorrhizae, they know these microbes are neutralized when added to unfiltered tap water containing chloramines hence why nearly all organic gardeners have an RO filtering system.
An RO system works by forcing a solution containing a mineral content through a very fine, semi-permeable membrane (ultra fine filter) that allows your solution (the water) through, but stops any larger molecules from passing through it. Thus purifying the solution of all dissolved minerals and producing you pure water.
Now putting aside the benefits of using RO or purified water, obligingly we must now go through the downside of RO water. RO machines produce waste water in the approximate ratio of one to three. So, for every litre of purified water produced, you will get three litres of waste water. The carbon filter and sediment filter on your RO purifier need to be replaced every three or four months, but the semi-permeable membrane will last for approximately two years. Another downside of an RO system is that, as well as removing all of the minerals that unbalance your nutrient solution, they also remove all the minerals that are useful to your plants.
Bicarbonates and carbonates present in tap water create an alkalinity that helps to buffer the pH of the water. These compounds help to raise the pH and neutralise the effects of any acids that are added to water - including those present in your nutrients, and also the ones put out by your plants as waste. By completely removing those with an RO system, the pH will be rendered unstable. To counteract this, once the water has been purified by the system, a small amount of tap water needs to be added, to slightly increase the EC and provide the buffer.

Calcium and magnesium which are both essential to plant development - will also be removed by the RO system and may need to be supplemented along with your base nutrient. This is because many of the nutrient companies formulate their recipe to cater for 'hard' water - already containing relatively high levels of calcium and magnesium - and therefore reduce the amount of these elements in their recipes, in order to prevent overfeeding. Using nutrients in RO purified water can lead to calcium and magnesium deficiencies. Adding high quality calcium and magnesium or more commonly known and referred to as CalMag, as a supplement to your RO water before adding any base nutrients and this will help to prevent these problems from occurring. Adding CalMag ensures your plants remain healthy and green right through to harvest. Lastly the rate of CalMag used will increase for gardeners who use coco as a medium. This is simply due to the fact that all coco competes with your plant for any Calcium.
In summary, yes the RO filtering system is worth having especially if you live in a hard water area. Or if you are an avid organic gardener and quality produce matters to you, and if it is really all in the taste, then a RO machine is definitely for you.
Reverse Osmosis and Water Filter Kits @ Go Grow
If you have any further enquiries regarding RO water or water filtering systems please feel free to pop into the shop or give us a call 0203 609 4067.