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Just like us, houseplants need vitamins and minerals in order to thrive. But they are not getting them from tucking into a healthy serving of fruit and vegetables, they are getting them from the soil they grow in and the water source they are exposed to.
This poses an issue when using RO water, as it has been completely stripped of its mineral content.
Thankfully for your plant babies, it is possible to add nutrients to RO water or your plant soil to counter this.
What to add to RO water for plants? Find out below!
Before we get into details, this was written with houseplants in mind, not larger-scale crop growing.
That said, you can add various things to your RO water to remineralize it and help your plants flourish. What you select will be based on what is best for the type of plant you are trying to grow.
All plants need these three nutrients to thrive, just in varying doses.
If you have multiple kinds of plants, look for the ratios in an NPK fertilizer. NPK fertilizer can be used as a base, and then if your plant needs more nitrogen, for example, you can add it from a different source. NPK fertilizer will come with a number to show its ratios. A 4-4-4 NPK has 4% nitrogen, 4% phosphorus, and 4% potassium.
Some plants prefer a granular fertilizer, and others prefer a liquid added to the RO water. Granular fertilizers are applied to the soil, and their nutrients are released every time the plant is watered, whereas liquid blends are diluted in the water and applied weekly.
There are also some natural options for boosting nutrients in the soil and water of your houseplants, such as banana peels for potassium, coffee ground for nitrogen, and eggshells for increased pH and calcium.
Adding sugar or salt to your plants is a risk, as sugar can attract bugs and promote mold growth, and salt can kill your plants in doses that are too high.
Reverse osmosis removes almost all minerals from your water. They include:
Nitrogen, phosphorus, potassium, calcium, and magnesium are some essential things that all plants need for growth, plus various plants will have different requirements for other minerals too.
All in all, most common plants need about 20 minerals for basic growth. As such, when choosing your remineralization agent, be sure to look for one that has as many of the essential nutrients your particular houseplant species needs and the ratios at which you should apply them.
RO water is basically water in one of its most pure forms. Free from almost all contaminants, it is close to 100% H2O. Reverse osmosis purification requires your water to run through an RO system, which has several stages of filtration, including
Your household water moves through these filters, eventually arriving in a storage tank and ready for you to use.
Also, there are different types of RO systems, such as portable countertop units that attach to your tap or under sink units that require a little more installation.
Chlorine has been added to our water supplies for years. This has been an amazing advancement in public health, as it kills waterborne pathogens that cause disease.
But some of our more sensitive plants don’t love it. Dracaena, Cordyline, and Calathea are examples of this. They all are chlorine sensitive.
Houseplants do best with water with a pH of around 6.0. RO water is usually pH 6.5, dropping down to 5.5 sometimes, particularly if you let it sit for too long before use.
5.5 isn’t considered too much of an issue, as the soil will usually buffer it anyway. Just note that too high or low water pH can lead to issues such as stunted growth, necrosis, leaf death, and brown spots.
If you have any questions about what to add to RO water for plants please don’t hesitate to leave a comment below!
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