In vertical farming, crops are grown indoors, under artificial conditions of light and temperature.It aims at higher productivity in smaller spaces. It uses soil-less methods such as hydroponics, aquaponics and aeroponics.
Vertical farming uses significantly less water and pesticides than traditional agricultural methods. Being indoors, the crops aren't subject to seasons and hence give high productivity year-round. Lettuces, tomatoes and green crops can be produced through this practice.
ARE YOU USING THE RIGHT WATER FOR YOUR PLANTS?
It is essential to use water with just the right pH - slightly acidic to neutral and low TDS (total dissolved solids) levels.
If you have been using tap water to make your hydroponic solution, you might be surprised to know that even tap water can possess undetected contaminants that can seriously harm your plants.
Visible clarity can be highly misleading when it comes to judging the purity of water. And, tap water can fluctuate in quality quite a bit. The last town or city down the river may have added numerous unwanted items in your water. Plants are susceptible to such fluctuations, more-so than humans.
Consequently, it becomes essential to have stable water quality. With it, you can adjust the pH while adding and maintaining nutrients according to your needs.
HOW CAN REVERSE OSMOSIS HELP?
One of the most common practices in vertical farming is to use reverse osmosis (RO) water in order to create your nutrient solutions. This water is made by running another water source – most commonly tap water – through a reverse osmosis system that removes a very large portion of the ions within the initial water source.
The idea behind using RO water is to have the best “base” for the construction of a nutrient solution. If your water starts up with some substances within it then the amount of control you have over composition is limited and therefore your results might suffer because of that. If for example your nutrients add 150 ppm of Ca. but your water already contains around 40-60 ppm, then adding so much Ca. might place you within a suboptimal spot. If your water contains a lot of carbonates, sodium, fluorides or other substances they can also cause significant problems within your hydroponic crop. Using RO water brings a “clean slate” that ensures that what you add is what you get. Since the RO process is known to remove the impurities like this and hence make the process to be viable with vertical farming.
In addition to that there are two main issues with using RO water.
-The first is that it’s a very energy intensive process – therefore a costly process – and the second is that the waste products of the RO process can create environmental problems. Additionally tap water already contains many nutrients necessary for plant life – mainly Mg and Ca. – so why would you remove these elements only to later add them again later on?
Surely you would rather save the energy from the RO process and use the nutrients within your water as part of your nutrient solution.
There are however some circumstances where using RO water is unavoidable. If you water contains more sodium than your crop can deal with, more than 50 ppm of chlorides or if there are more than 10 ppm of fluoride then you will need to use RO water because those elements in those quantities are not going to be good for your plants.