So you have your hydroponics garden set up and you are now down to the fine details. The type of water you use could be critical to a successful hydroponics garden. Do plants grow better with tap water or is distilled water for plants better?
Good old H2O is essential for all life on Earth. Plants require water to grow, but not all water is good.
Tap water around the world is filled with fluoride and other chemicals that can harm plants. The pH balance of water must be also optimum for fauna, but most water contains impurities.
However, distilled water has gone through a distillation process rending it pure and balanced.
Table of Contents
- 1 How Water Affects Your Plant’s Growth
- 2 What Is Distilled Water
- 3 Why Distilled Water is Useful
- 4 Is Distilled Water For Plants Better Than Tap water?
- 5 distilled Water or RO water for hydroponics Gardens?
- 6 3 diffrent ways to Make Distilled Water at home
- 7 Can I use tap water for hydroponics?
- 8 The Role of Water in Hydroponics
- 9 Using Tap Water – What’s the Big Deal?
- 10 Solutions for Using Tap Water
- 11 Recommendations for Tap Water
- 12 you use tap water for hydroponics? The Verdict
How Water Affects Your Plant’s Growth
Water is an essential element for all plants. Depending on the genetic makeup of a plant, will determine if the plant needs more water or less, and some plant’s genetic makeup allow them to survive during a drought.
Plants absorb water through their roots, which travels up their stem, through xylem vessels, to either their leaves, flowers, or fruit. Water carries nutrients that it absorbs from the soil, such as calcium, magnesium, and potassium.
If a plant receives too little or too much water, it can have a damaging effect on them. If there is too little water, the nutrients can’t be absorbed, and the growth will eventually stop.
They will also not appear healthy, because they will start to wilt or shrivel up and their leaves will dry up, turn brown and eventually die.
If there is too much water the roots can rot and they are unable to receive enough oxygen and other nutrients. It can also cause the plant to become lazy, so it will no develop or maintain its root system, which will eventually cause it to die.
What Is Distilled Water
Water is not found pure, (with a pH of or close to 7), in nature. Something will always dissolve in it, which is why distillation is used to create distilled or pure water.
Steam distillation is the most common form of producing purified water. It combines evaporation with condensation to create pure water.
In short, the water droplets that are created from condensation is collected to create pure water. This water has had the major of the common impurities or soluble substances removed from it, such as organic chemicals, bacteria, viruses, etc.
Why Distilled Water is Useful
The type of water that is used is also important. Distilled water is as close to pure water as can be found, most of the impurities have been taken out of it. Some tap waters contain chemicals which can build up in the soil of the plant.
Some tap water is considered “hard,” or contains a lot of minerals in it, which some plants cannot handle. Also so households use water softeners.
The water softeners add high levels of salt to the soil and deplete the nutrients from the soil. Another problem with tap water can be the pH level of the water.
If the water is too acidic or alkaline, the plants are unable to proceed in using the water to gain its nutrients. If the water is too acidic (that is with a pH below 7), it reduces the amount of calcium, magnesium, and potassium the plant receives.
If the water is too alkaline (with a pH above 7), the calcium builds up and stops the plant’s ability to absorb nutrients. One way of making sure your plants are getting the correct type of water is by using distilled water.
Is Distilled Water For Plants Better Than Tap water?
Plants that live indoors, in greenhouses and nurseries of gardens in urban areas have a higher chance of buildup from chemicals or minerals in the plant’s soil. These plants don’t have a chance to wash them away like outdoor plants can with rainwater.
These plants have a higher chance of not getting the proper nutrients with the buildup. One way to prevent this is by using distilled water. Since distilled water is pure water, with no chemicals or minerals, there is no chance of chemical or mineral build-up.
Solutions For Loss Of Minerals – Indoor Plants or Greenhouses
Distilled water has all of the impurities taken out of it, which includes minerals.
Some minerals that are removed from the water are essential to the growth of plants. One way to combat this is to add plant food to the soil to make up for the minerals lost.
distilled Water or RO water for hydroponics Gardens?
When using aquaponics or hydroponic gardening, water replaces the soil. Without soil, there is no way to filter out the impurities, which can cause an increased and quicker buildup of chemicals and minerals.
Distilled water also allows you to have complete control as to what is put into your systems, and in turn what goes into your plants.
Loss of Minerals and pH levels – Hydroponics
In hydroponics, water takes the place of soil, so it is crucial to make up for the lost minerals. Two minerals that are lost, when using distilled water calcium and magnesium. Cal-Mag is a type of nutrient solution that should be added to hydroponic systems.
These nutrients, not only help to make your plants grow, but they also help to balance out the pH of the hydroponic system.
The pH levels in hydroponics is another important thing to check. Distilled water has a pH level of 7, which, is not found naturally. Also when pure water mixes with CO2, it causes the water to become more acidic.
The ideal pH level for plants is around 6 because plants are able to draw the most nutrients at this level. So, you must continually check the pH levels in the tank.
The Cal-Mag supplement also helps to keep the pH level in check
So you don’t necessarily need distilled water if your water source is safe. However, there is a big plus when using distilled water.
You don’t need to worry about impurities in your water, or if those impurities build up in the soil around your plants.
Distilled water is cleaner and healthier for your plants, and they will help to grow the plants to their full potential.
3 diffrent ways to Make Distilled Water at home
You can buy distilled water at the store or by a water distiller. However, if you want to make your own, there are three common methods for making distilled water.
Method 1- Glass Bowl
Items needed: 5-gallon stainless steel pot, glass bowl, lid, ice, water, stove, clean storage containers
Possible needed items: round baking rack, tongs, hot pad holders
- Fill the pot half about halfway with water.
- Set the glass bowl inside the pot. It is important to make sure that the bowl floats if it doesn’t place the round baking rack on the bottom of the pot and set the bowl on top of it.
- Place the lid upside down on top of the pot and fill with ice. This will create the condensation, with a hot/cold barrier.
- Boil the water in the pot. As the stem begins to rise, it will condense on the lid, and then fall into the bowl.
- Continue until you have as much pure water as you want.
- When finished, shut off the stove, and take the lid off.
Note: Take the bowl out of the pot. Be careful not to burn yourself, this is when the tongs and/or hot pad holders would come in helpful You can also leave the bowl in the pot until the bowl cools down if you prefer
Store the water once it is cool.
Method 2- Glass Bottles
Items needed: 2 glass bottles (preferably one with an outward neck curve), 5-gallon stainless steel pot, duct or gorilla tape, a bag of ice/ice pack, water, stove, clean storage containers.
- Fill one bottle with water. About 5 inches from the top.
- Join the two bottles together. Make sure they are secured tightly with duct tape or gorilla tape.
- Fill the pot with water. Enough to cover the bottle filled with water.
- Tilt the bottles to about a 30-degree angle. Lean the empty bottle on the pot’s rim. The bottle with the outward neck makes it easier to collect the distilled water.
- Place the ice on the top of the bottle that is outside of the pot. This creates the hot/cold barrier.
- Continue until you have enough water.
- Store in containers.
Method 3- Rainwater
Items needed: Clean container, rain, outside, clean storage containers
- Place the container outside. It will collect the rainwater.
- Leave it outside for two days. This allows for the minerals to dissipate.
- Store in storage containers. *It is also a smart idea to boil or treat the rainwater if you live in a place that has a lot of chemical debris in the rainwater.*
Can I use tap water for hydroponics?
Water is the basis for growing plants with any method, but with hydroponics it plays an even more significant role.
The contents of your water before you add nutrients has a huge impact on how nutrients interact, and how your solution ultimately affects your plants.
Understanding the impact of tap water and how to reduce its negative effects will result in vigorous growth and larger yields in your hydroponic garden.
The Role of Water in Hydroponics
In a hydroponic system plants grow only in water. There is no soil or other organic surrounding that acts as a barrier for plant roots.
This means that there is a direct interaction between plants and the water they uptake, which also contains all required nutrients for growth.
Without a protective barrier to soak up excess nutrients or chemicals, if it’s in the water, it will get into your plants.
So if you’re using tap water in your hydroponics system, whatever is in your tap water will get into your plants.
Using Tap Water – What’s the Big Deal?
If you’re using tap water for hydroponics, it’s likely due to necessity, where else would you get your water from?
So you must use it, but if you understand what’s in your water, you can do a lot to control and reduce its negative impact.
What’s wrong with using tap water in hydroponic cultivation?
Chlorine and Chloramines
Chlorine and chloramines are both added by water treatment plants to kill bacteria and pathogens harmful to humans. While this is a good thing, it can be very harmful to plants.
These chemicals will kill any beneficial bacteria or fungi in your system. These microbes help to increase the amount of nutrients that plants can uptake.
Without these beneficial organisms, plants get less nutrients, therefore grow smaller and yield less
Although plants need chlorine in small amounts, tap water contains much more than plants regularly need. To add to this, many hydroponic nutrients contain chelates, which help keep nutrients suspended in water.
When chelates come into contact with chlorine, they bond and further increase the amount of chlorine taken up by plants.
Too much chlorine causes a nutrient toxicity (too much of a nutrient), which stunts plant growth.
Chelates in Hydroponic Nutrients
Chelates are used in hydroponics to help plants uptake more nutrients. Certain nutrients will not remain suspended in water, and will combine with one another to form compounds that plants can’t uptake.
Chelates remedy this issue by forming bonds with these nutrients that keep them suspended in the water, and make uptake by plants easier.
For nutrients you want getting into your plant, this is great! But certain undesirable elements in tap water are more easily absorbed by plant roots because of chelates.
When chelates come into contact with chlorine, they bond and allow more chlorine to enter your plants. This causes toxicity as it gives the plants much more chlorine than they need.
Tap water may be considered ‘hard’, which means it has a high ppm. This means that there are extra dissolved elements in the water, which can end up in your plants.
Water with a ppm (parts per million) of 150 or greater has a lot of Calcium and Magnesium in it.
Although plants need both nutrients, the molecules of these elements in tap water are too large to be absorbed by roots. This means they will collect in your system and stain and clog every part of your system.
By starting with a high ppm, you have less room to add nutrients to your system. If you want to feed your plants an 800PPM solution, but have 250PPM out of the tap, you have little room left.
This can make it easy to burn your plants (toxicity) or unintentionally not provide them enough nutrients.
It is relatively unlikely that your tap water will come out at the perfect pH to water your plants with. This means that you need to adjust the pH in order to properly feed your plants.
Adjusting pH usually involves adding an acid or a base to lower or raise your pH. The chemicals in most pH adjusters also kill any microbes in your system, resulting in the same problem caused by chlorine.
Some pH adjusters contain salts of Phosphorous or Potassium. Plants also need these, but by adding excessive amounts you can cause a toxicity or lockout of another nutrient.
Solutions for Using Tap Water
So as we have discussed, there are problems with using tap water in hydroponics. But thankfully, there are many solutions to using it.
How to Remove Chlorine from Tap Water?
Chlorine can easily be removed from your tap water by allowing it to sit outside in direct sunlight for 24 hours. The UV rays will break down the chlorine, thus removing it from your water.
This can be problematic if your system is large, so using a carbon filter or Reverse Osmosis (RO) filter would be more appropriate.
Other options include additives like campden tablets and sodium thiosulfate (commonly used in aquariums).
What is the Best Way to Remove Chloramines from Your Water?
Chloramine is more difficult to remove than chlorine. It will not evaporate for a long time, and so must be filtered out. Carbon filters or an RO system are the best options to remove chloramine.
Not all tap water contains chloramine, to find out, just call your municipal water supply and ask if chloramine is added to the water.
How to Soften Hard Water
Excess salts in tap water must be mechanically removed using a carbon filter, or a reverse osmosis system.
You can also dilute your tap water with distilled or RO water to lower your PPM.
Solving pH Problems
Filtering is the best solution for this issue. Filtering will remove excess salts and usually produces water with a pH around 6.0.
This is ideal for hydroponics, and at the very least will reduce the chance of adding too much salt-laden pH adjuster.
Recommendations for Tap Water
The following are a few recommendations that will help in diagnosing and treating your tap water.
Reverse Osmosis System: HydroLogic 150 GPD Stealth Ro150 RO Filter
- Removes 98%+ of all contaminants in your tap water
- 3-Stage RO unit, 1 RO membrane, Green Coconut Carbon Filter, cleanable...
- The Stealth-RO150 includes your choice of both 1:1 and 2:1 waste to product...
RO systems come in many shapes, sizes, and prices; this unit is reasonable priced around $150. I have used this unit myself for both hydroponics and aquaponics, and it has served me well.
These systems will filter out all unwanted contaminants from your tap water and leave you with nearly pure water, perfect for hydroponics.
The downside to an RO system is the upfront cost and it wastes 2-3 times the amount of water than it filters. There is also upkeep which requires that you replace the carbon, sediment, and membrane filters eventually.
Faucet Filter: Brita Tap Water Filter System
- This complete Brita faucet water filter attaches to your standard faucet...
- Get great-tasting water without the waste; by switching to Brita, you can...
- The space efficient design attaches directly to your faucet to give you a...
A filter attached directly to your tap is a great way for smaller growers to efficiently remove chlorine and excess salts. For $20 to 30, this filter will easily make your tap water safe to use with your plants.
PPM Meter: HM Digital TDS-4 Pocket Size TDS Tester Meter With 0-9990 Ppm Measurement Range
- This TDS tester is ideal for all water purification applications,...
- ATC (Automatic Temperature Compensation) ; Advanced microprocessor...
- The Sleek design of the TDS-4 is perfect for personal or commercial use
A PPM meter is already essential in hydroponics, so if you don’t have one, get one!
This is just an example of a good quality meter for a good price. With a ppm meter, you can easily check the ppm of your tap water to check if the ppm is too high.
You can also (and should) use a ppm meter to regularly check the ppm of your hydroponic solution.
PH Meter: Bluelab PENPH PH Pen
- Backlit LCD display
- Fully waterproof
- Automatic Temperature Compensation
As the name suggests, you can use pH Meter to monitor your pH. Use this to determine if your tap water pH needs to be adjusted. As with the ppm meter, this is just a great tool to have in hydroponics.
This meter is pricier, but cheaper pH meters are prone to inaccuracy and can stop functioning quickly.
you use tap water for hydroponics? The Verdict
After looking at what’s in tap water and how it can affect your plants, it’s clear that tap water and hydroponics don’t mix. But that doesn’t mean you can’t grow hydroponically with it.
If you follow the recommendations outlined here, you can make any water safe for your plants. Ultimately, how you remove the contaminants in tap water will depend on how big your operation is.
If you’re a hobbyist, using sunlight to remove chlorine and a drinking filter to lower ppm should work fine. If you’re a bit larger, you’ll want to stick with a filtration system.
Lindsey Hyland grew up in Arizona where she studied at the University of Arizona’s Controlled Environment Agriculture Center. She continued her gardening education by working on organic farms in both rural and urban settings. She started UrbanOrganicYield.com to share gardening tips and tactics. She’s happy to talk about succulents and houseplants or vegetables and herbs – or just about anything in a backyard garden or hydroponics garden.