How much water does a hydroponic system use

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quality hydroponic garden needs specific measurements to avoid overflowing and contamination and help your crops grow effectively. But how much water does a hydroponic system use? It depends on how large or small your garden will be, so the amount of water may vary. 

A hydroponic system requires maintenance to ensure your nutrient solution is clean so you can grow hydroponic plants like tomatoes. The water used will also depend on what hydroponic technique and the companion plants.

But knowing how to clean a hydroponic garden is one thing, and using water for nutrient solutions for your plants’ growth is another. There are still base water measurements for a standard hydroponic system reservoir you may want to consider before building your hydroponic garden.

What is the minimum water requirement for hydroponics?

Finding the correct water requirement means knowing your hydroponic system’s reservoir size. It will depend on what kind and how many plants you’ll harvest. Also, consider how big the crops will be once fully grown.

Once you have all this jotted down, you can use the standard reservoir sizes based on plants according to Hyalite:

  • small-sized plants: 1.5 to 2 liters per plant (minimum)
  • medium-sized plants: 3 to 5 liters per plant (minimum)
  • large-sized plants: approximately 10 liters per plant (minimum)

One way to refill the right amount of water after cleaning your hydroponic system is by marking the water level with a permanent marker so you won’t need to measure again. Farmers Weekly also states that you need 5 to 7 liters of water for a fully-fledged hydroponic system.

However, the main thing to pay attention to is water quality. Bacteria in filthy water can spread contamination over your plants. Making sure your water is clean is vital since it is the heart of your garden.

What is water uptake?

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Water uptake pertains to how a plant’s roots absorb water nutrients to be processed and released as a gas, later absorbed by the stomata. It also happens in traditional soil planting. But why is it beneficial in a hydroponic setup?

In a nutshell, water is absorbed and processed throughout the plants for nutrients. According to Filipino gardener Ms. Rebueno, the soil is a buffer for roots to uptake water. But since a hydroponics system does not have soil, there is no buffer. Roots are directly submerged in a nutrient solution, making it easier to absorb more water for more uptake.

But you will need to be careful as some plants may need extra care with ph levels as they can die if the ph has not settled in the solution.

Factors that affect water uptake in hydroponic plants

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Aside from knowing how much water does a hydroponic system use, there are also different external factors that can affect water uptake in a hydroponic system aside from its Ph levels. You will also need to consider the weather and environment of your garden to ensure the following factors won’t stunt your plants’ growth by fluctuating the system.

Temperature and wind

Wind and temperature are known to increase or decrease the vapor pressure deficit (VPD) in a plant, the measure of dryness in the air. According to Greenhouse Grower, higher air temperature or low relative humidity can affect water uptake in plants. 

Less water in the air / low humidity = High VPD

Lots of water in the air / high humidity = Low VPD

High VPD means more water evaporates from the leaf, causing better water uptake. On the other hand, low VPD is when the air is full of water or humid, causing less evaporation from leaves.

VPDs serve as an indicator of plants’ water use or a sensor for irrigation. The humidity or temperature of an area may vary per region or location. It’s best to ensure it is not too humid and creates just enough sunlight or temperature for plants to perform water uptake. 


Wind greatly affects water uptake by stripping water away from open stomata, increasing water loss in leaves. Aside from outdoor settings, it can also affect areas like greenhouses where electric fans can produce air that can cause plants nearby to lose water faster.

Small wind currents and low relative humidity combined also cause drier spots on benches or beds that lessen water uptake. However, water use may differ; humidity, temperature, and air may not always be controlled and vary, and effects can differ according to where the plant is.

Plants on the edge that are more exposed to air may dry up more than plants in the center. The bench’s center area is often more humid and has less air due to the protection or shade of neighboring plants around them, causing more water uptake and less water use.


Light is also known to affect a plant’s growth process the strongest. For water uptake, high levels of light can increase water loss in the stomata. Light may be vital for photosynthesis, but too much can cause disrupt the water uptake process.

Do you need hydroponic reservoirs?

There are different hydroponic systems you can try for your gardens, such as the nutrient film technique or the floating raft system. It is where you plant roots to be submerged in the solution needed to provide nutrients necessary for your plants’ growth. Reservoirs are often paired with an air pump to push water up to be absorbed by the roots.

Roles of hydroponic reservoirs

The different hydroponic techniques also vary in parts, but a reservoir is one of the staples as it carries your plants’ nutrient solution. The hydroponic or nutrient reservoir has many vital roles aside from providing nutrient uptake.

Nutrients concentration

While it carries the nutrient solution, reservoirs can also keep tabs on your nutrient solutions’ levels. You will need to frequently check your reservoir nutrient concentration with your EC meter and regular Ph check system.

Solution temperatures

Reservoirs can also help regulate the nutrient solutions into the preferred temperature. North Slope Chillers state that 65℉ to 80℉ is the best water solution temperature range to maintain optimal nutrient absorption and healthy roots.

Sunlight protection

Hydroponic reservoirs must be covered or colored in dark colors as it also prevents exposure from direct sunlight from contaminating or causing algae growth. You can also plant large plants to help shade smaller plants in your garden.

Water oxygenation

Aside from providing nutrients, the reservoir also helps maintain oxygen levels in the water. Plant roots and leaves need oxygen to perform photosynthesis. It works hand in hand with an air pump to the air stone that pushes oxygen bubbles up to be absorbed by the roots for food-to-energy conversion.

Floating raft system

The floating raft or deep-water culture system (DWC) is best known for growing vegetables like lettuce plants. This hydroponic system technique places plants on polystyrene or foam sheets as floating rafts while the roots are in the water or the nutrient solutions.

Holes are drilled into floating rafts to fit the net cups for plant support. The location and amount of holes depend on what kind of crops you’re planting, but sticking with the lightweight plants known for hydroponic gardening is the best option for the floating raft system.

Only leaf-type vegetables like lettuce or bok choy are suitable for this hydroponic system technique, drenching plants in water solutions.

Wick system

The wick system is the easiest technique in the hydroponic system family. It uses a wick to absorb and transfer the nutrient solution to the growing medium where the plants are. Popular growing mediums are Coconut Fiber, Pro-mix, Perlite, and Vermiculite. 

However, the cons of a wick system are that large plants or plants that need lots of water may absorb the nutrient solution faster than the wick system provides, fluctuating it. A wick system also consumes less water and nutrients while being one of the best options for water-loving plants. 

You can start with seeds and cuttings as the wick system is slow due to low-volume liquid movement and the plants you use for the system are low maintenance. 

Reusing materials is also a great way to build a wick system since it doesn’t need high maintenance. Smart Garden Guide states you can create a mini wick plant system with a two-liter plastic bottle for the reservoir and absorbent material for a wick like yarn, rope, or strings. 

Wick systems are a great hydroponic technique for beginner gardeners who want to take their time learning aquaponics!

Drip system

Drip systems are a beginner-friendly hydroponic technique that provides the best irrigation methods for growing plants. It is also known as the trickle or micro-irrigation system, using small emitters to drip the water solution into plants. 

The drip system is also widely suited for bigger hydroponic gardens than the wick system as it consists of a network of feeder lines to deliver water to plants. It uses traditional irrigation in a non-soil growing system to make more versatile crops in the city.

Another importance of drip systems is that they are a no-waste technique because of the low drip irrigation. Evaporation takes place through moisture from soil drip from the plant’s base. It slowly provides nutrients without putting the spare solution to waste!

But how does a drip system work? It also uses air pumps in the reservoir as roots drink through drip emitters! You can set up your drip system vertically or horizontally than other hydroponic systems, making it great for beginner and advanced hydroponic gardeners.

Wrap-up: How much water does a hydroponic system use?

The amount of water hydroponic systems you should use will depend on what type of system you’re using, how big your garden will be, and what plants will you be growing!

While we’ve also discussed the different uses of a reservoir and some types of hydroponic systems where reservoirs are vital, knowing the size of your hydroponic reservoir and the size of the plants you’ll be growing is one of the best basis for your water levels.

Hydroponic water requirements include reservoir size, water pumps, and water source. Some systems still need fertilizer for the plant but roots will gather nutrients from the reservoir.

There are several factors in a hydroponic growing garden, but the general rule is always to utilize enough clean water to prevent nutrient solution fluctuations. Most plants that grow during daylight hours only ask for proper water needs, such as water vapor and irrigation, to produce energy and food so they can grow healthily, especially in a hydroponic system!