Is It Better to Water Plants With Filtered Water?

If you are a home horticulturalist, then you know that water–both in terms of quality and quantity, can make the difference between flourishing plants, and dead plants. Many a new plant-owner has faced the sting of defeat when they realize that they didn’t quite have the knack for feeding their new green friends the right type of water. We’ll cover some basics of water filtration and plant life in what follows, covering commonly-asked questions by gardeners and indoor plant aficionados, such as is purified water good for plants? and more.

Watering Plants and Why Water Quality Is Crucial

Whether you are a human, animal, or plant, if you’re alive, water is what keeps you that way. Water is one of the most basic ingredients necessary for life as we know it, and plants rely on the water that nature brings them–unless they are indoors, in which case they rely solely on you. Plants differ widely in how much water they need, with cacti needing far less water than a citrus plant, for instance. Check with the recommendations on your plant, but as a general given rule, you should water your indoor plants once or twice a week. Give the plants roughly ⅓ the volume of their planter pot in water, and they should do fine. You are on the ground floor, though, so pay attention to what your plant might be telling you.

Common Types of Water Used for Watering Plants

There are a few options when it comes to water sources for plants, with tap water being the easiest and most obvious for most people. Tap water can be a fine source of water for many plants, but it does carry some risks. Depending on where you live, your tap water may not be of the highest quality, especially if you live in a developing country, or a very large city anywhere in the world. Even in developed countries, the great press and crowd of so many people in one place (such as Manhattan) creates terrible water conditions, with more human waste, sewage, and garbage, than city treatment plants can easily keep up with.

Even if you live in a rural area in the United States, you may still want to avoid drinking tap water, or using it on your plants. Be aware of local water conditions, and know what is in your local water. Water quality differs dramatically from region to region, and it changes over time as well. Each year, the federal government mandates that every city in the nation conduct a city water quality test, and make the findings publicly available, so you should have up-to-date information on the water in your area, unless you are on a private well.

Well water is usually safer for plants than city water, because of the lack of chlorine, chloramines, and other disinfectants put into city water to treat microbial life. Well water is often rich in nutrients and minerals, which can make it great for a garden, or for indoor plants.

Beyond tap water–either city or well–you can chose to water your plants with filtered water of various types, which we will discuss below.

Understanding Water Quality and Plant Health

Water is a very powerful solvent, meaning that it dissolves other substances on contact, absorbing them into itself. This is both a good and a bad thing. It is good, because it allows water to be an ideal vector for spreading healthful things, such as calcium, magnesium, and selenium, which most organisms need to survive, but it is bad because it can do the exact same thing with lead, arsenic, and chromium, to name just a few dangerous things we don’t want to be drinking. Dangerous contaminants in water can harm or kill plants in the same way they can prove deleterious to human and animal health, so it’s important to give your plants the right kind of water.

Benefits of Using Filtered Water for Plants

There are a lot of different ways to filter water, and each have their specific advantages and disadvantages. A very basic filtration setup may combine sediment and carbon filter cartridges to remove particulate matter and dissolved chemicals, whereas more robust, multi-stage reverse osmosis water filter systems will remove nearly all TDS (total dissolved solids) from water, with even more aggressive post-treatment options such as deionization available for plants with specific needs, such as carnivorous venus fly traps.

Is Purified Water Good for Plants?

So is is purified water good for plants? Different filtration methods will yield water that is optimal for different plants, but aside from unique plants like the fly-trap, which has very specific needs, almost any plant can benefit from a pass through a sediment and carbon filter, as this will help strain out physical particulate, as well as chlorine, which is very damaging to plants. Salt is another big plant killer, so don’t use softened water on your plants, if you can avoid it.

Comparative Analysis

In this section, we will go through a few water options for your plants, with the pros and cons for each.

Sediment & Carbon Filtered Water

A basic pass through a sediment and a carbon filter is usually enough for most water to see a significant improvement.

Reverse Osmosis Water

RO water is a mixed bag, generally speaking, because it is excellent at removing just about everything from your water, meaning that your plants are getting mostly pure H2O, but that isn’t necessarily a good thing. Plants need other minerals and nutrients that an RO system will usually strip out. Using nutrient-rich fertilizer is a way to counteract this, however.

Deionized Water

Deionized water is usually created by first running water through an RO membrane, and then through a special deionizing resin, which removes nearly all TDS in water, leaving it with a completely neutral charge. This means that deionized water isn’t great to drink, because it lacks all of the nutrients and minerals that water normally contains, but it is good for certain plants, such as the venus fly-trap.

Rain Water

Rain water is what most plants are stuck with, but if you have an option for your indoor plants, it might not be the best. Rainwater can contain trace particulates from smoke and smog through carbon emissions, as well as relatively high salt content, especially in coastal regions, all of which can be damaging to plants.

Compost Water

If you have a compost pile, throw some water in there, and use it to water your plants. The water will pick up trace amounts of good nutrients from vegetable ends, eggshells, and so on, making it very nutrient-dense. Just don’t put anything dangerous or toxic in your compost pile.

Boiled Pasta Water

If you are someone who always wants to make the most out of everything, consider saving the water you boil pasta in. Most enriched-flour pastas contain healthful minerals, which will leach into the water, and be great supplements for your indoor plant friends.

Practical Tips for Watering Plants

Don’t overthink it, and don’t panic if you use less-than-ideal water for a session or two. Plants are robust, and have their own defense mechanisms against contaminants, so a little bit of problematic water won’t necessarily spell their doom. Your best guide is the plants themselves–if they look vibrant and healthy, keep doing what you are doing. If they are brown, wilting, or otherwise struggling, rethink your watering regimen.

Conclusion

As with so many things, there is no strict right or wrong answer here, but rather a variety of plausible options. Get to know your local water conditions, and the needs of your favorite household plants, and tailor your approach to those conditions. Knowledge is power, for you, and your photosynthetic friends.

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Becky

Meet the award-nominated UK lifestyle blogger behind Spirited Puddle Jumper – a mum of three living in South East London! Becky shares the real ups and downs of family life, parenting tips, and lifestyle inspiration, proving that being a mum doesn’t mean you stop being fun or having other interests! Follow along for honest insights into UK family life and opinions on a whole range of topics, from travel and food, to beauty reviews, home and DIY, business and health and wellness.