Looking for a correct method on how often do you change the water in hydroponic systems? For the healthy growth of the plants, the quality of water plays a key role. The main reason being, it carries the necessary nutrients. And in hydroponics gardening, deep water culture is the simplest system.
And you are able to maintain the correct nutrient level and pH level of the water, your yield will always be of the highest quality. This can be achieved by a regular change of water.
In my experience, you must change the water every week or two. However, it depends on the size of the system and the crop. You can always use devices like pH meter, EC meter, TDS, etc. which will help you know when it’s time to change the water in the reservoir. Apera Instruments Premium Series PC60 Multi-Parameter Pocket Tester is a great tool for hydroponic growers because you can measure different parameters for changing water directly with the system.
How Often Do You Change The Water In Hydroponic Systems?
The first thing you need to understand is what are the factors or elements that affect the change of water. It is the pH and conductivity of the water that requires you to change the water. So by measuring these factors, you can decide if the water in the hydroponic system needs to be changed.
Measuring Ph
The pH is a measure of acidity or alkalinity of any solution. The pH of 7 is considered to be neutral. And anything below 7 is considered acidic and anything about it is considered alkaline.
In order to have healthy crops, you need the pH to at an optimum level. By maintaining optimum pH level ensure the solubility and availability of the important nutrients in the water.
If the pH of the water drifts in any direction of the optimum range, the plant won’t be able to absorb the required nutrients. With any nutrient deficiency, the plant won’t be able to grow efficiently.
There is a much deeper science when it comes to pH for hydroponics systems. But for quick understanding, you must know that the optimum range for the hydroponic crops is 5.5 to 6.5. And the commercial hydroponic growers use an even narrow range of 5.8 to 6. So always keep the pH of the water in the hydroponics system within this optimum range.
Whenever the pH of the water is off you will see the effect on the crops or in water. For example, in the case of iron deficiency you will say yellow foliage. In the case of calcium deficiency, you will see scales on the water itself. But these are extreme conditions.
If you want to maintain the pH at an optimal level all the time then you will need a pH meter. Dr.meter PH100-V High Accuracy Pocket Size pH Meter is one of the best pH meters for hydroponics systems. Using the pH meter you can keep track of the pH level and change the water whenever it goes off.
Electrical Conductivity
Electrical conductivity is another way to know when to change the water in the hydroponic system. When measuring the electrical conductivity in water, it shows what is the nutrition mixture in the water.
To understand the concept of conductivity in the water, you must know distilled water has no conductivity. And when you add any salt or minerals, the water becomes conductive. Higher the concentration of salt in the water, the higher is the conductivity.
However, one thing this test doesn’t tell is what kind of mineral or salt is present in the water. But if you want to know how often do you change the water in hydroponic systems, you don’t need to identify the content of the water. You just need to find what the conductivity of water is and from that data, you can decide if you want to change the water or not.
You can measure the electrical conductivity using the EC meters. HoneForest Water Test Meter is what I use to measure the conductivity of the water. You can also use TDS meters as they also measure the conductivity in the water.
The most optimum range of EC for plants is 1.2 to 2.0. If conductivity is below this range you will need to add more nutrients to the water. And if the conductivity is more, you will have to either change water or add more water to the system.
What Is The Best Way To Change The Water In Hydroponic Systems?
Changing the water efficiently and effectively is the key if you want your hydroponic system to work at optimum capacity. There are different hydroponic systems but the way you change water remains the same because each of the systems uses some or other types of reservoir tanks.
There are two ways to change the water in hydroponics:
1. Partially
In the first case, you are not actually changing the water but adding water to maintain the pH of the water already in the system. Whenever you observe that the water level in the reservoir tank has reduced, you need to check the pH and add water according to it.
The most important thing to remember that the water you are adding must have a pH of 7. It is the most neutral form.
With this method, you will have to add the water several times in a week or even daily if the reservoir tank is small compared to the crops it supports. Make sure you note the amount of water you add and also the pH or the conductivity of the water for every instance.
One big disadvantage of this method is that even though you add water regularly you have to change the water every week or every 3-4 days depending on the size of the system. This needs to be done because of the issues like salty scale formation, nutrient imbalance, and other impurities.
2. Completely
In this method, you completely change the water in the hydroponic system. Compared to the above method this method provides you more control over the pH and the nutrient content in the water.
This method also ensures the hydroponic system is at the optimum level because of the complete turnover of the water. It is much like doing the hydroponic reservoir maintenance.
With this method, you will have to do some extra steps compared to the previous method. You will have to adjust the pH of the water to the optimum level. This optimum level is different for each crop. You can check out this article to learn about the required pH for different crops.
There are different ways of adjusting the pH of the water. The most popular method is the use of pH adjusters. There are plenty of them specifically designed for hydroponic systems. Old household methods like the use of vinegar or baking soda won’t work for hydroponics.
To find the most suitable pH adjuster for your crops. We recommend using General Hydroponics HGC722080 pH Control Kit. It is the most tursted adjuster available on amazon.
Final Thought
There is no fixed rule on how often do you change the water in hydroponic systems. It all varies from system to system, crop to crop and weather to weather.
But from my experience, if you keep an eye on the pH and conductivity of the water, you can make precise changes.
An important thing to remember is to always use the most reliable and accurate equipment.
