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You May Be Overlooking One Key Factor In Hydroponics: Water Quality

Water quality isn’t a concept that most people consider when they start hydroponic farming. But maybe they should. Water has a significant impact on the overall quality and taste of your produce. It can affect the fullness and development of your crop, meaning that the plants you grow in poor quality water will be less productive.

In this blog, we’ll describe the different aspects of water quality that you need to understand as a hydroponic grower and explain some elements of hydroponic systems that ensure that water quality is maintained throughout the entire farm.

Can I Put Tap Water Inside My Hydroponic System?

Putting tap water directly inside your hydroponic system isn’t a great idea. Water is treated inside the system with a reverse osmosis system, which removes impurities, nutrients and organic matter from the water. Water that isn’t treated with reverse osmosis typically contains higher amounts of chemicals and metals like iron, manganese and zinc. This is typically referred to as a water’s “hardness.”

If you used tap water inside a hydroponic system, your plants might not react in quite the same way as they would if you used water purified by reverse osmosis. Plants grown with tap water are thinner, shorter, smell less strongly and have less color than crops that grow with RO water.

Is It Good to Use Natural Water in a Hydroponic System?

Natural water isn’t ideal for use in hydroponic systems for many of the same reasons that tap water doesn’t work. It features high amounts of inorganic salts, like calcium, magnesium, potassium and sodium, and carbonates, nitrates, bicarbonates, chlorides and sulfates.

How Does Water’s Hardness Affect Plant Growth?

The hardness of water can affect plant growth in many ways. Hard water is more difficult for plants to pull nutrients from, requiring them to expend more energy to feed themselves. Hard water can also affect the roots of the plants, hindering their development and reducing the level of oxygen exchange in the root zone.

With this in mind, it’s easy to understand the value of starting your hydroponic system with a bedrock of high-quality water. So how do hydroponic systems, including those we sell, ensure the water they’re using is standardized to provide crops with excellent-quality water, every single cycle?

The solution can be found in the purifying reverse osmosis systems, which every drop of water must pass through before being used in the system.

How Can Reverse Osmosis Systems Improve Water Quality

Reverse osmosis systems (RO), purify water by pushing water through a semi-permeable membrane. By applying pressure to salinized water with a high-pressure pump, you can produce purified water with a lower concentration of salts and dissolved solids. This water provides your hydroponic system with a stable supply that ensures that your nutrient solution is standardized for every cycle.

Our RO systems need to be maintained around every 6 months, though they may require more frequent maintenance if used intensively. Maintenance is easy, as you only need to remove the old filter, clean the empty cylinders, and then install the new filter.

A lettuce plant growing in a hydroponic shipping container farm.
Ensuring water quality is key to producing vibrant, healthy plants cycle after cycle.

How Does Electric Conductivity (EC) Affect Water Quality

Electric conductivity is a measure that describes the amount of available nutrients in the water supply. Higher EC levels have higher concentrations of nutrients, while lower EC levels have less. Elevated EC levels can create nutrient imbalances and stress, while crops growing with diminished EC levels are characterized by nutrient deficiency and reduced growth.

Electrical conductivity is especially important in hydroponic water quality. In traditional soil-based systems, crops are buffered from the effects of suboptimal pH and EC levels because they are covered by a layer of soil. In hydroponics, growers must be more careful, as crops don’t have anything separating them from excessive nutrients.

A key reason for purifying water before adding it to the system is because tap water typically features a higher EC level because of the increased amount of nutrients like calcium, magnesium, sodium and potassium. Ideally, RO systems produce water that has an EC close to 0.0, helping growers calculate their water and nutrient proportions appropriately.

Plant Signs of Low Electric Conductivity

  • Discolored or misshapen leaves
  • Diminishing crop yield
  • Stunted growth, especially in the root zone

Plants Signs of High Electric Conductivity

  • Wilting and curling leaves, especially in the lower plant leaves
  • Leaf necrosis
  • Mottled leaves

Because many of the signs for low EC and high EC are similar, it’s important to test the EC of the water before attempting to fix the issue. While you might recognize there’s a problem, you can’t take specific action before checking on the makeup of the nutrient solution.

Water leaving a hydroponic shipping container farm through a PVC pipe.
Reverse Osmosis Systems expel brine water as part of the purification process. Even though you can’t use this for hydroponics, you can still use it for other uses. For instance, you can water outdoor plants, wash windows, and clean cars with the expelled water.

Tips for Ensuring Proper Water Quality

Make incremental changes to your water supply, instead of making large, drastic alternations in a short period of time that could shock your plants.

For example, a high electrical conductivity can mean that there are more nutrients present, but it can also mean that there’s a high level of salinity in the solution. Because of this, it’s important to consider the reasons this may be.

If you measure stable or increasing EC levels, and you haven’t recently refilled your reservoir with more nutrients, you may need to reduce the salinity of the solution by adding more water or flushing the system with fresh solution.

Regularly measure your electrical conductivity to gauge the health of the solution you’re feeding to your plants. If you notice EC staying the same while also observing slowing plant growth, it may be a sign that your system needs a deep cleaning.


In conclusion, water quality is a fundamental aspect that should not be overlooked in hydroponic farming. As discussed, the type of water used directly influences the productivity, development, and overall quality of crops. The use of tap water or natural water, with their impurities and hardness, can result in suboptimal plant growth and diminished yields.

To address this, hydroponic systems employ reverse osmosis (RO) systems, ensuring that water is purified and standardized for each cycle. The significance of maintaining an appropriate electrical conductivity (EC) cannot be overstated, as it directly impacts nutrient balance and plant health.

Monitoring and adjusting EC levels, along with regular maintenance of RO systems, are essential practices for hydroponic growers to maximize the potential of their crops.

By understanding and prioritizing water quality, hydroponic farmers can create an environment conducive to robust plant growth, leading to healthier and more vibrant produce.

Contact us and learn more about how you can easily maintain the water quality of your hydroponic system with our custom-built container farms.

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