Have you ever heard of mineral-rich water? If not, don’t worry—you’re not alone. It’s a relatively new term and concept that has only recently become relevant in the world of cannabis cultivation. The idea is pretty simple: some areas have naturally occurring hard water with an abundance of minerals, which can cause problems for plants when used as irrigation water for growing marijuana.
But what does it mean to grow cannabis with mineral-rich water? And more importantly, why does it matter? It’s important to first understand what mineral-rich water is and why it’s a problem for growing marijuana plants. Let’s talk about the basics and how you can solve this issue, in order to get back to enjoying your favorite strains without worrying about any side effects from this hidden threat.
What’s in “mineral-rich” water?
One would likely assume that water is a good thing for plants, but there are certain types of water that can actually be harmful to your crop. You might already know that plants need nutrients in order to grow, and the most common nutrient is nitrogen. But what you might not realize is that the source of those nutrients matters. In short, some things are better than others when it comes to giving plants what they need and nothing more—and one of these things is minerals.
Mineral-rich water contains salts such as calcium chloride and potassium chloride which can be beneficial for your cannabis plants if used properly. However, too much salt will make them sick or even kill them! If you’re using tap water from an area with high mineral content (like the midwest) then it’s likely that yours has high amounts too; if so then this guide will help you keep your plants safe while still enjoying their benefits.
Is mineral-rich water dangerous to your plants?
So, is mineral-rich water dangerous to your plants? The answer is yes. If you’re growing in soil, the high potassium and calcium levels can cause nutrient lockout in your plants. This means that your nutrients will not be absorbed by the roots and will instead just sit on top of the soil like a layer of dust. Your plant won’t be able to use them until it rinses away this extra layer of minerals that are inhibiting absorption.
Root rot and nutrient toxicity are also common issues with mineral-rich water. Root rot can occur when there’s too much sodium in your water which causes root damage and inhibits growth for weeks or months after transplantation into new soil with fresh water (or even if you’ve never moved). Nutrient toxicity happens when a plant takes in too much nitrogen from fertilizers used during cultivation; this causes tissue damage and can ultimately lead to your plant’s demise.
How can I prepare my water for cannabis plants?
If you’re growing cannabis, it’s a good idea to check the mineral content of your water. Minerals can interfere with nutrient uptake and pH levels, thereby limiting the effectiveness of your fertilizer. You can use either a water softener or RO filter to remove these minerals from your water supply. If you use RO filtration, be sure that the system has enough capacity for all of your plants’ needs; otherwise, they will suffer nutrient deficiencies as well as toxicities from over-feeding them (too much magnesium or sodium bicarbonate).
You can also add calcium sulfate and magnesium sulfate salts in order to increase alkalinity and reduce acidity respectively (if needed). This is particularly important if you have hard water which contains high levels of calcium carbonate (CaCO3) because this compound binds up other nutrients like nitrogen by forming insoluble calcium nitrates which cannot be used by plants. It is therefore advisable not only to monitor but also correct any elevated levels detected using an appropriate buffer agent such as sodium bicarbonate (NaHCO3).
Hard/mineral-rich water can be treated and even safe for growing cannabis.
Hard water can be treated and even safe for growing cannabis.
It may come as a surprise to learn that hard/mineral-rich water is not necessarily bad for your plants. It all depends on how you treat it. Treating mineral-rich water to make it safe for growing cannabis is done by using a water softener or RO filter, which removes minerals from the water before it reaches your grow system. Water softeners remove hardness by replacing calcium with sodium ions, while RO filters remove minerals by passing the whole stream of water through an ion exchange membrane.
It is worth noting that hard water can be treated in many ways. All these materials have different advantages and disadvantages, so make sure you do some research before deciding which one suits your needs best.
Water softeners and RO filters as a solution to hard water
Water softeners and reverse osmosis (RO) filters are two different ways to treat hard water. Each uses a different process to remove the minerals from the water, but they both work well for growing cannabis in hard water regions.
What is reverse osmosis? Reverse osmosis (RO) filtration is a process that uses pressure to force purified water through a membrane. This removes many impurities and other unwanted elements from your source water. RO membranes are usually made of cellulose acetate or polyamide materials, although there are some newer versions on the market today that use ceramic fibers instead of plastics.
What is a salt-free softener? A salt-free softener works by adding sodium chloride (table salt) into your source water at its source point before it reaches your home or garden irrigation system. The sodium chloride reacts with calcium carbonate in the source water and creates calcium chloride which has no negative impact on plants as it passes through them because no ions are added back into their root systems so they don’t continue absorbing any minerals beyond what was already present in their soil bedding mix (substrate).
Grow Flow offers solutions to your mineral-rich water
Grow Flow experts can help outfit your growhouse with the perfect water solution for your needs. Grow Flow offers water softeners and reverse osmosis solutions you cna use, whether you grow your cannabis with soil or hydroponics. Backed by over 70 years of experience, every water treatment plan is specialised to each of our customer’s needs. Just as the water quality and mineral makeup in your area may change, Grow Flow is always available for new water testing and system adjustments as needed.