How Often to Change Hydroponic Water? (My Best Guide)

Plants are so independent that they do not even need soil for their food production; all they need is sunlight, air, water, chlorophyll and some nutrients. The water and nutrients the plants require are indeed received from the soil, but it’s not always a necessary medium. 

Hydroponics is the perfect method that helps plants not lose their energy while retaining important nutrients and water from the soil. But, do you know how often to change hydroponic water?

Honestly speaking it depends on the size of the container, so there can’t be a definitive answer. But, in most cases you don’t need to change hydroponic water more than two times in a month.

How often to change hydroponic water
How often to change hydroponic water?

Why is it compulsory to maintain a water system for hydroponics?

Proper water management is very necessary for the optimal growth of plants in a hydroponic set-up. Since water is the primary carrier and solvent for other supplements for the plant, any impurities present in the water can lead to unwelcome results for the plant’s health.

Problems like undersized growth and mineral toxicity are just two of the many health issues your plants might face if appropriate water management guidelines for hydroponics are not followed. Uncontaminated water aids in the growth of plants that are both healthy and have had rapid growth. 

The crucial elements you must take care of while maintaining a hydroponic system:-

  • The pH – The required pH of most hydroponic plants is between 5.5 and 6.5. The pH assists in determining the absorption of the vital elements essential for the crops.
  • The cleanliness of water – As mentioned earlier, clean water aids in the optimal growth of hydroponic plants. Using distilled water or water from an uncontaminated reservoir and treated properly will bless you with disease-free thriving plants.
  • The environment – To ensure overall appropriate hydroponics maintenance, the air, light and temperature must also be controlled. Too much or too little of anything is never good, so consider these factors while taking care of your precious plants. 

It can not only lead to the development of unwanted conditions within your plants but can even cause them to die if not properly looked after. Checking up regularly, changing the water and ensuring that the water is aerated properly are examples of how you must keep your plants alive.  

How often to change hydroponic water? (The Actual Answer)

About once or twice every month, depending on the size of your container. You can keep adding water to the garden until and unless it’s time to change the water of the entire tank. Over time, the pH of the water in the tank tends to go up or down, but adding extra water seems to correct the issue.

When it’s time to completely alter the tank’s water, you should be mindful of not shocking the plants while pouring in new water. The newly supplied water must not be very different than the previous one. Preferably, the water must come from the same source as the earlier one. 

Why Should You Change the Water of Your Hydroponic System?

The advantages of timely changing the water of your hydroponic system are as follows:

To Set Up a Proper Water Control Mechanism

Routinely changing the water of your hydroponic tank helps you take charge of the entire water management of the system. Topping off the water quite often while there’s water in the tank aids in evening out water evaporation by the heat of the sun or bright lights and balances the pH level of the water.

Changing the water fully should be of lesser frequency than topping off.

To Prevent Biofilm Accumulation

If water is not changed routinely, the proximity between the plants’ roots and the tank’s water directly underneath the roots might lead to algae or fungal build-up.

If the bacterial or biofilm build-up is not treated adequately, various diseases may emerge, leading to the decline of the health of your green friends. So, regularly top off or alter the water within the tank to evade risks.

Factors Impacting Water Changing Schedule for Hydroponics

A few factors affect the schedule of water changing in a hydroponic system. They are listed below:

Factors Impacting Water Changing Schedule for Hydroponics
Factors Impacting Water Changing Schedule for Hydroponics
  • Evaporation – Water evaporates in a hydroponic system due to the sun’s heat or the artificial bright lights used in a hydroponic system for the plants to survive. But to balance the water that evaporates and maintain the required water level, you must keep adding or changing the water whenever the need arises. 
  • Plant types and density – The plant types and densities also play crucial roles in determining the schedules of water changes in a hydroponic cropping system, mainly based on the amount of water and mineral requirement of the kind of plant.
  • Size of the water reservoirs- Even the size of the water reservoirs acts as a factor influencing the routine of nutrient solution changing. The tinier tanks usually need a solution alteration more often due to reasons like bacterial buildup and so on. 
  • Topping off your solution– Topping off can be a great way to ensure pH balancing and fighting water evaporation in the hydroponic water setup. It reduces the need to change the water once or twice a month. 
  • Perfect pH levels – Altering the solution also helps maintain a perfect pH standard since the pH standard can turn unbalanced over time within the solution tank of your hydroponic setup.

Kinds of Water Alterations for Hydroponics set-up

The two kinds of water alterations in your system are as follows:

Water Alterations for Hydroponics set-up
Water Alterations for Hydroponics set-up

Full water refills

Dumping the entire nutrient solution present in the solution reservoir of the garden is necessary to do almost once or twice a month, as said earlier. Altering the water fully might be a sudden shock to the plants, so you’ll need to be careful while doing so.

Implementing a brand new fertilizer or preventing large algae or bacterial biofilms are some of the major causes to show you why routinely changing the full water is essential.

Topping off the tank

Topping off the tank is again an amazing way to ensure your plants are well taken care of. Keeping the appropriate pH measure, evening out the evaporated water because of heat and transpiration, and controlling your water management system are reasons to add extra nutrient solution into your tanks. The addition must essentially be within a gap of 2 and 3 days. 

How to Refill the Nutrient Solution for Your Hydroponic Set-up? 

Listed below are the steps to change the water for your set-up. 

How to Refill the Nutrient Solution for Your Hydroponic Set-up
How to Refill the Nutrient Solution for Your Hydroponic Set-up? 
  • First, remove the plants and their containers from the water tanks.
  • Pour out the used-up water from the water reservoir to clean it up
  • Clean the tank properly to not leave any residue or dirt or germ behind
  • Fill up the solution tank with nutrient-infused water 
  • Put back the bed of plants on the solution tank set-up

Repeat 2-3 times a month and remember to preferably use water from the same source as earlier if no problem was noticed beforehand with the water. 

How to Test to Detect the Change of Solution?

 Here are a few ways how you can test your hydroponics to ensure the change of water:

pH Testing

pH testing is necessary to determine optimal pH levels for the plants. To test the solution, add some drops of nutrient water to a pH-sensitive dye, and you will learn about the required pH.

Repeat this often during the initial stages and, later, to check up on your plant’s comfort. If the pH seems to be unbalanced, topping it off with more water aids in balancing out the pH level.

EC testing

EC testing means measuring the Electrical Conductivity of your nutrient water. It helps us determine the number of essential elements that must go into our nutrient solution.

EC testing assists you in knowing the number of dissolved salts in the water and topping off your solution reservoir aids you in balancing out excess salt accumulation within the water tank. When the EC measurement increases, it means the plants absorb more water than the nutrient and vice-versa.

Frequently Asked Questions (fAQs)

Some questions that people often ask while trying to maintain hydroponics are as follows:

Does having proper EC measurement mean having good nutrient quantity?

No, it does not mean much. It just informs you about the number of elements in your solution. There might even be waste buildup, but the EC testing won’t tell you that. Only depending on EC testing might, thus, ultimately lead you to harm your plants.

How often should I do EC testing?

Preferably every day. Checking up on your plants daily through EC testing is necessary, as is creating alterations to your nutrient water every seven days.

Other reasons to change the hydroponic solution

● To renew the solution or add more ingredients to ensure proper growth.
● To add a variety of fertilizer.
● To clean the tank and prevent contamination.
● To overcome the issue of collection of stagnant water.

The Conclusion

The investments for installing a hydroponic cropping system might be a bit pricier for some folks. The maintenance cost of the entire set-up, along with the cost of the nutrients and fertilizers, also adds to the cost incurred for the hydroponics system.

Yet, you’ll observe that the benefits and returns are worth the investments in the long run. 

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top