If you’re thinking about growing plants in water rather than in soil for the first time, be it strawberries, tomatoes, or something else, you need to know all about hydroponic growing systems and how they work before you even try to get started.
In short, hydroponics is a method of growing fruits, vegetables, and other plants in self-contained systems that utilize water, light, nutrients, and a substrate other than soil.
That said, understanding what type of water is best for use in hydroponics is one of the most important aspects of your learning curve.
Distilled water is the most preferred type of water for hydroponic systems due to its lack of harmful contaminants. Once mixed with tap water, it is the best option. Alternatively, tap water that has undergone reverse osmosis filtration is another great choice.
The Importance of Water Type in Hydroponics
Water quality is a critical factor in hydroponics as it directly impacts the health and growth of plants. The type of water you use can influence the nutrient balance, pH stability, and overall success of your hydroponic system.
- Nutrient Delivery: The water you use is the medium through which essential nutrients are delivered to your plants. Poor water quality can lead to imbalances or deficiencies in nutrients, affecting plant health and yield.
- pH Control: Water with stable pH levels helps maintain a consistent growing environment. Using water with extreme pH can hinder nutrient absorption and lead to plant stress.
- Mineral Content: Different water sources contain varying mineral concentrations. High mineral content in water can disrupt nutrient ratios and potentially lead to buildup or deficiencies over time.
- Microbial Balance: Water quality influences the growth of beneficial and harmful microorganisms in your hydroponic system. Contaminated water can introduce diseases that harm plant roots.
- System Longevity: Water quality affects the cleanliness of your system. Water with excess minerals or impurities can lead to clogs, blockages, and reduced system efficiency.
- Consistency: Consistent water quality ensures stable conditions for plant growth. Fluctuations in water quality can stress plants and hinder their development.
- Customization: Understanding your water’s composition allows you to adjust nutrient formulations to meet the specific needs of your plants.
Choosing the right water type—whether tap water, distilled water, or treated water—depends on its characteristics and suitability for hydroponic use.
Regular testing, treatment, and monitoring of water quality are essential practices to ensure optimal plant growth and the overall success of your hydroponic endeavors.
Hydroponics Basics
Light, water, carbon dioxide, and oxygen are necessary for growing things. Soil isn’t.
Hydroponic growing systems replace soil with another material that supports the plant’s roots, allowing plants to grow directly in water.
Basic hydroponic growing methods include:
- Water Culture: One of the most popular hydroponic growing methods. A medium holds the roots, the plant floats directly on top of the water and nutrients, and a pump supplies oxygen into the water.
- Wick System: The most basic hydroponic setup. Plants grow in a tray on top of the water, and a wick draws water and nutrients into the growing medium.
- Ebb and Flow: A hydro method where a pump and timer flood the growing medium with water and nutrients that then drain back into the reservoir.
- Nutrient Film Technique: A very simple hydro-growing method. Plants are placed in baskets with roots suspended above a constant flow of nutrients and water.
- Drip Systems: Another of the most widely used types of hydroponic systems; a pump and timer connected to a tube or hose drip nutrients and water into the growing medium.
- Aeroponic Systems: An advanced method for growing hydroponically; plants are suspended in the air as with NFT systems, but rather than a constant flow of nutrients, the roots are misted every few minutes.
What Kind of Water Is Used in Hydroponics?
Water needs to be specially treated to remove harmful chemicals and contaminants before use in a hydroponics system.
Distilled and purified water are the easiest to use as they have already been purged of chemicals, minerals, and bacteria. That said, tap water, filtered water, well water, and even rainwater can be used for hydroponic growing after they are treated.
How To Treat Tap Water for Hydroponics
Treating water for use in a hydroponic growing system is rather simple:
- Place the tap water in direct sunlight for one to two days to remove chlorine via UV rays.
- Next, apply one tablet (good for up to 20 gallons) for removing chloramine. There are also tablets that remove both chloramine and chlorine at the same time, allowing you to skip step one. Additionally, running water through an active-carbon filter removes chloramine as well.
- If your tap water is hard water, a reverse osmosis filter needs to be used to remove the calcium and magnesium.
- Finally, run the water through a debris filter to remove any leftover debris in the water.
Now your tap water is properly treated and ready to be introduced to your hydroponic system.
Is Distilled Water Good for Hydroponics?
Distilled water is one of the best choices for hydroponics as it has already had all harmful contaminants removed. That means the only nutrients your plants receive are the ones you purposefully introduce to your water.
However, you may want to add some treated tap water to create a healthy pH level as distilled water has a neutral pH reading of 7.0.
Can Rain Water Be Used for Hydroponics?
Rainwater is absolutely okay to use in hydroponic systems. However, due to heavy metals in the air and contaminants collected from runoff surfaces, like gutters and roofs, rainwater needs to be treated before you use it in your growing system.
Is Well Water Safe for Hydroponics?
Water from underground wells is not a safe choice for use in hydroponics due to the large number of contaminants found in it.
Because the water comes from deep within the ground, enormous amounts of contaminants, possibly including herbicides and pesticides, can leach into well water. Test the water from your well, and you might be very surprised by what you discover.
Can Purified Water Be Used for Hydroponics?
Purified is a great choice for use in hydroponic growing operations as it allows for complete control over what nutrients the plants absorb. But, it is far from necessary as long as you properly treat your water first.
What Is Reverse Osmosis Water?
Reverse osmosis water is created through a special filtering process that involves pushing the water through membranes to remove debris, minerals, molecules, and harmful contaminants. It is one of the very best types of water to use in hydroponics.
Water Purification Methods for Hydroponics
Water purification is crucial in a hydroponic setup to ensure that the nutrient solution provided to the plants is clean and free from contaminants. Contaminated water can lead to poor plant growth, disease, and other issues.
When selecting a water purification method for your small home hydroponic setup, consider factors such as the quality of your water source, the types of contaminants present, your budget, and the specific needs of your plants.
It’s also essential to monitor the quality of your water regularly to ensure that your chosen purification method is working effectively and that your plants are thriving.
Here are some water purification methods suitable for a small home hydroponic setup:
- Tap Water Treatment: If your tap water is relatively clean and doesn’t contain excessive amounts of contaminants, you might be able to use it directly in your hydroponic system. However, it’s a good practice to let the tap water sit out for a day or two to allow chlorine and other volatile compounds to dissipate before using it in your system.
- Carbon Filtration: Activated carbon filters can effectively remove chlorine, chloramine, and certain organic compounds from water. A filter like this is relatively inexpensive, easy to install, and simple to use. They are a good first step in water purification for hydroponics.
- Reverse Osmosis (RO) Filtration: RO filtration is one of the most effective methods for purifying water. It uses a semipermeable membrane to remove a wide range of contaminants, including minerals, heavy metals, and pathogens. An RO system may consist of several stages, including sediment filtration, carbon filtration, and the RO membrane itself.
- UV Sterilization: Ultraviolet (UV) sterilization is used to kill or inactivate bacteria, viruses, and other microorganisms present in the water. UV light disrupts the DNA of these pathogens, rendering them harmless. UV sterilizers are typically installed in the water line before it enters the hydroponic system.
- Ozone Treatment: Ozone is a powerful oxidizing agent that can effectively disinfect water by killing bacteria, viruses, and other microorganisms. Ozone treatment systems can be used to sanitize the water before it’s introduced into the hydroponic system. However, ozone should be used with caution as it can also be harmful to plants at high concentrations.
- Ion Exchange Resins: Ion exchange resins can help remove minerals, heavy metals, and other contaminants from water by exchanging them with less harmful ions. These systems can be particularly useful if you’re dealing with hard water or water with high mineral content.
- pH Adjustment: While not a direct water purification method, adjusting the pH of your water is essential in hydroponics. You might need to use pH-adjusting chemicals or additives to ensure that the nutrient solution’s pH is suitable for optimal nutrient uptake by the plants.
How To Make Nutrient Water for Hydroponics
Making nutrient water for hydroponics is much easier than it sounds:
- Purchase a micronutrient mix/water-soluble fertilizer and Epsom salts.
- Read the instructions for mixing with water.
- Add the correct amount of fertilizer to the water (probably 2 teaspoons), and stir it well.
- Mix in a teaspoon of Epsom salts for every gallon of water.
That’s it! Now your water is loaded with the right type and amount of nutrients for hydroponics. Just remember that you’ll need to add more nutrients every week to every week and a half, and you’re good to go.
Correct pH Level for Hydroponics
Depending on what you are growing, the best pH level for Hydroponics is generally between 5.5 and 6.0 and 4.0 to 5.0. Vegetables prefer a higher pH (5.5 to 6.0), and berries require lower levels (4.0 to 5.0).
How To Test Hydroponic Water
Hydroponic water requires two types of testing; pH and EC. Both types of testing are most accurately measured with meters. To do so, power the meter on, stick the probes into the water, and read the display on the meter.
Alternatively, pH test strips can also be used to test hydroponic water also. Simply dip the strip into the water for a couple of seconds and pull it back out. The results will appear after approximately 10 seconds.
How To Adjust the pH Level of Hydroponic Water
Adjusting the pH level of the water in your hydro system is relatively easy, even if you don’t have a stock of professional supplies.
If the pH level is high, all you need to do is add something containing alkaline, such as baking powder, to lower it.
On the other hand, when pH levels in your water test low, adding citrus raises them up. Lemon juice or white vinegar are a couple of the most common household items used for this purpose.
What Is EC in Hydroponics?
EC stands for “Electrical Conductivity,” and it is a crucial parameter in hydroponics. It measures the ability of a solution to conduct an electric current, which is directly related to the concentration of dissolved salts, primarily mineral nutrients, in the solution.
In hydroponics, plants receive their nutrients directly from the nutrient solution instead of the soil. The EC of the nutrient solution provides a way to gauge the concentration of these essential nutrients.
As plants consume water and nutrients from the solution, the concentration of salts changes, affecting the solution’s EC.
Monitoring the EC helps hydroponic growers maintain the right nutrient balance, preventing overfeeding or underfeeding the plants. A proper nutrient balance ensures healthy plant growth and optimal crop yield.
Ideal EC for Hydroponics
The ideal EC for hydroponics can vary depending on the type of plants you’re growing, the growth stage of the plants, and the specific nutrient solution you’re using. Different plants have varying nutrient requirements, and EC values should be adjusted accordingly.
Generally, younger plants or plants in vegetative growth stages require lower EC levels, while mature plants or plants in the flowering/fruiting stages may need higher EC levels.
EC measurements are typically given in units of millisiemens per centimeter (mS/cm) or microsiemens per centimeter (µS/cm). A common range for EC in hydroponics is between 0.8 and 2.5 mS/cm, although this can vary.
It’s crucial to follow the recommendations provided by your nutrient solution manufacturer or consult specific guidelines for the plants you’re growing.
How To Measure EC in Hydroponics
To measure EC in hydroponics, you’ll need an EC meter, also known as a conductivity meter or TDS (Total Dissolved Solids) meter. This one is very affordable and reliable. Here’s how to measure EC:
- Start by calibrating your EC meter according to the manufacturer’s instructions. Calibration ensures accurate readings.
- Collect a small sample of your nutrient solution. Make sure the sample is free from debris and air bubbles as they can affect the reading.
- Immerse the EC meter’s probe into the sample. Ensure the probe is fully submerged and not touching the sides or bottom of the container.
- The EC meter will display the electrical conductivity reading in mS/cm or µS/cm. Take note of the reading.
- Compare the measured EC value to the recommended range for your plant type and growth stage. Adjust the nutrient solution concentration as needed to bring the EC within the desired range.
Water Pumps for Hydroponics
The purpose of water pumps in hydroponic growing systems is dual; to pump water and move nutrients.
Depending on the type of hydroponics that you’re working with, the details may vary a bit. For this reason, we discuss water pumps for hydroponics in further detail in the sections below.
Types of Water Pumps Commonly Used in Hydroponics
There are two types of water pumps that are most commonly used in hydroponic setups: submersible and inline.
- Submersible water pumps: These pumps are directly placed into the water, are cooled by the water, and rely on hoses and fittings to move the water and nutrients through the rest of the system.
- Inline water pumps: This style of pump is attached to the outside of the system, is cooled by the air, and transfers water and nutrients from inside the holding tank to the tray and growing medium.
Which Water Pump Is Best for the Home Hydroponics Gardener?
Submersible water pumps are generally considered the best and easiest to use for home hydroponics gardeners. This is due to the fact that home hydroponic systems tend to be smaller and require less power to move water.
Water Pump Timers – Do You Need One?
The water pump timer is a key component to many, but not all, hydroponic systems.
For example, aeroponic, drip, and ebb and flow all heavily rely on timed water and nutrient movement. NFT systems can do with or without water pump timers.
On the flip side, water culture and wick systems don’t utilize water pumps at all. Therefore, a water pump timer is not part of the system either.
Is an Air Pump Necessary?
Air pumps aren’t necessary for hydroponics other than in deep water culture setups.
That said, air pumps assist in dissolving oxygen in the water as well as preventing disease and algae growth and can be used for hydroponics regardless of not being a requirement for the system to work properly.
How Often Should You Change Hydroponic Water?
The average home hydroponics system needs its water fully changed every two to three weeks like clockwork. In between full water changes, feel free to top off your water levels by adding small amounts of water every so often.
Keep in mind that sometimes you may need to change out your water supply early. For example, if your system begins growing abnormal amounts of algae, change the water immediately.
If not, the harmful bacteria from the algae may produce disease and infect your plants.
Likewise, when testing pH levels in your water, if an extreme unbalance is noted, changing the water right away is always the best course of action rather than trying to doctor up the pH levels by adding ingredients as mentioned in earlier sections of this article.
Additionally, when you are changing hydroponic water, make sure to wash out the tank and scrub it as well.
Avoid using chemical-based cleaners or soap, and stick with elbow grease and/or plant-friendly cleaning solutions.
Can Hydroponic Water Be Recycled? | Disposing of Used Nutrient Water
The best way to safely dispose of used water from a hydroponic system is to recycle and/or reuse it.
This can be done by:
- Draining the used water into a bucket or container.
- Mixing equal amounts of tap water with the used water.
- Pouring the water down a drain in the bathroom or kitchen.
- Using the mixture to water plants in self-contained pots with no drain holes.
Or, you can purify and dispose of it normally instead of recycling and reusing it. The best way to do so is:
- Using a reverse osmosis filtration system, UV disinfection system, or pasteurization equipment.
- Testing the water’s pH level, which needs to be between 6.5 and 8.5 before it is considered safe for disposal.
- Checking the EC level of the water, which should read as close to 0.0 as possible.
- Disposing of the now-safe water however best suits you.
Water Temperature for Hydroponics
In all types of hydroponics, the correct water temperature is absolutely critical for successful operations and regular/healthy plant growth.
The water temperature in any hydroponic system should be monitored and maintained between 65 and 80 degrees Fahrenheit.
Temperatures higher or lower than the suggested 65℉ to 80℉ cause massive shock to plants, starting with the roots and their ability to intake the proper amount of nutrients and water.
Failure to quickly correct the situation results in dead plants.
Managing water temperature for hydroponics can be achieved by:
- Setting your system up in a shady area.
- Painting the tanks/reservoirs.
- Using a swamp cooler or chilling coil.
- Burying the tanks/reservoirs in the ground.
- Keeping the water levels topped off.
- Using larger tanks/reservoirs.
- Keeping the temperature outside of your system between 75℉ and 80℉.
Perhaps one of the most overlooked aspects of home hydroponics, maintaining the right water temperatures is an easy disaster to avoid if you are simply aware from the get-go and practice one or more of the above-mentioned tips.
Hydroponic Water Levels
The correct water level of hydroponics depends on the type of system you’re using. The bottom line is that your system’s water should keep your plant’s roots wet, but the stems should always be dry.
The proper water level makes sure this is always the case.
In ebb and flow, water levels should be roughly 2 inches below the growing medium. That way the roots are never exposed to too much air.
On deep water culture setups, the correct water level is 1 inch or so below the net/pot. However, if the bottom of the plants are dry, the water needs to be slightly raised.
Likewise, if the plants’ bottoms are sloppy wet, the water needs to be lowered a bit.
NFT, aeroponics, wick, and drip systems don’t have a suggested water level due to the difference in how they utilize and deliver water.
Can You Overwater in Hydroponics?
Overwatering can and does occur in hydroponics. Typically, overwatering happens when:
- The water level is too high and oversaturation of the growing medium in NFT and deep water culture system occurs.
- The pots in drip systems don’t have good enough drainage and become filled with water.
- Growing mediums in various systems become flooded with too much water or are flooded too often.
- Water pump or timer malfunctions occur.
Frequently Asked Questions
Can I Make My Own Hydroponic Nutrient Solution?
Yes, you can create your own hydroponic nutrient solution. Homemade nutrient solutions can be cost-effective and allow you to customize the nutrient ratios for the specific plants you’re growing.
However, it’s essential to have a good understanding of plant nutrient requirements and the chemistry behind nutrient solutions to create a balanced mix. You’ll need to source various water-soluble fertilizers containing essential macro and micronutrients.
Nutrient solution recipes can vary based on the type of plants, growth stages, and the specific hydroponic system you’re using.
It’s recommended to consult reliable hydroponic resources or guides to ensure your homemade nutrient solution provides the necessary elements in appropriate proportions.
Do You Have To Use Distilled Water in Hydroponics?
While you don’t necessarily have to use distilled water in hydroponics, the quality of water you use is important.
Tap water or well water can contain minerals, chemicals, and impurities that might affect the pH and nutrient balance of your hydroponic system.
Distilled water is often preferred because it lacks these contaminants, providing a clean and consistent starting point for mixing nutrient solutions.
However, using distilled water exclusively might lead to a lack of essential minerals over time.
Many hydroponic growers use a combination of distilled or purified water and tap water, treating the tap water to remove chlorine and chloramines before mixing with nutrients.
Can I Use Spring Water for Hydroponics?
Using spring water for hydroponics is possible, but it’s important to know the mineral content of the spring water.
Spring water can vary significantly in terms of its mineral composition, which can impact the nutrient balance in your hydroponic system. It’s recommended to have the spring water tested for its pH, EC, and mineral content.
If the spring water contains an excessive amount of minerals, it might not be suitable for hydroponics without dilution or blending with other water sources.
If the mineral content is within an acceptable range, spring water can be a good option for providing essential nutrients to your plants.
Does Boiling Water Purify It?
Boiling water is an effective method to kill or inactivate many types of microorganisms, including bacteria, viruses, and parasites, that might be present in the water.
Boiling water at a rolling boil for at least one minute (or longer at higher altitudes) can make it safer for consumption by destroying most harmful pathogens.
However, boiling water is primarily a method for disinfection and does not remove other contaminants such as heavy metals, chemicals, or dissolved solids.
For hydroponics, if your water source contains excessive mineral content or impurities, boiling alone will not effectively purify the water for use.
Other methods like filtration, reverse osmosis, or specific water treatment technologies might be necessary to ensure the water is suitable for your hydroponic system.
A Final Word About Water Use in Hydroponics
Successful water use in hydroponics requires specially treated water, correctly mixed nutrients, well-balanced pH and EC levels, in addition to proper water levels and temperatures, and more.
Trying to set up and run a hydroponics system without understanding proper water use is like trying to cook burgers on an old-fashioned grill without understanding anything about charcoal and fire; it’s bound to end in disaster.
If you’re unsure of something, revisit this article as many times as necessary, or seek additional resources.