A hydroponic garden can be tricky. When soil and sunlight don’t do their jobs, it is up to you, the gardener, to grow your plants. You need to know when and how much water and plant nutrients to add to your hydroponic solution, but it is equally important to know when to remove them.
The hydroponic solution should be changed periodically when the amounts of water equal the capacity of the tank, typically every two weeks. Nutrients, bacteria, and fungi are prevented from accumulating too much. If you are having trouble maintaining your base water’s pH and electrical conductivity, more frequent changes may be necessary.
When Should You Change Your Hydroponic Water?
The process of draining and reusing your reservoir can be both time-consuming and costly. Maintaining this balance is imperative for your hydroponic system.
Over time, an imbalance of ratios can occur, resulting in harmful organisms flourishing, stunting the growth of your plants. This creates conditions that are conducive to disease or even to the death of your plants.
Adding Your Solution
Due to evaporation and transpiration, the water level in the reservoir will decrease as you grow your hydroponic plants. Adding a little clean water to your hydroponic solution periodically will help prevent this water loss in your system.
“Topping off” involves adding fresh water gradually to maintain fluid levels. Unlike regular water, nutrient compounds like nitrogen, copper, and zinc aren’t as quickly thrown away like water. And, having them become too concentrated can become harmful to your plant, especially to the roots.
The exact frequency of topping off varies from person to person. A good rule of thumb is to do it every 2-3 days, but you can do it every day. When topping off, it’s essential to measure how much water volume you’re adding.
As soon as you have filled your reservoir to the maximum level, you will need to change the entire solution. It usually takes around two weeks (or 10-20 days), but it’s better if you can be specific. Plants grow exceptionally well in hydroponics, but science, not an art, and precision are critical!
In chemistry, pH is the concentration of hydrogen ions, or acidity, in a solution. Although hydroponics is a complicated concept, it’s easy to understand.
In direct contrast to pH, plants are negatively affected by pH if they cannot absorb nutrients from the solution well. In the event of a pH imbalance, roots will not be able to absorb the nutrients effectively. Most species prefer a pH range between 5.5 and 6.5, although some species prefer a higher or lower pH value.
You can measure pH easily. It is possible to purchase pH test sticks cheaply at your local hydroponics supply store (also available at pool and aquarium supply stores) or online. Watch them change color in your fresh solution, and check the back of the box to see what pH they correspond to. At least to start with, it’s a good idea to check your pH daily.
Other Reasons To Change Your Hydroponic Nutrient Solution
There are a few more situations in which it would behoove you to change your hydroponic solution:
- When you change your nutrient ratios. Changing the ratio of your nutrient levels will require a thorough clean-up of the tank and a new solution if you’re making any significant changes.
- It is easy to see signs and symptoms of nutrient imbalances and bacterial growth.
The following symptoms may occur:
- Green leaves turn yellow from chlorosis
- Your plant develops a purplish tint, which is called “purpling.”
- Necrosis of sections of leaves and plant roots
You should discard your water solution if you notice that some parts of your plant are growing much slower than others or if your plant as a whole is growing very slowly.
What is the shelf life of hydroponic nutrients?
Assuming you drain and clean your nutrients each day and top off the system with a volume of water each day, hydroponic nutrients can typically last 7 – 10 days. As plants absorb nutrients in the system, the nutrient strength will diminish.
Can you grow hydroponics without a nutrient mix?
Certainly, but plain water won’t provide sufficient nutrients for plant growth and plant health. Choosing hydroponics has the advantage of eliminating the need for soil to provide nutrients to plants, and you can also precisely control the amounts of nutrients they receive.
Is there anything I can do with my used up hydroponic solution?
Hydroponics solutions require a lot of work, so it’s disappointing and wasteful to throw out the plant juice full of nutrients. It’s okay to show some love to your plants outdoors, too! You can spread the diluted nutrient water on your flowerbed or outside garden if you dilute it 50/50 with tap water.
You may flush your used hydroponic water down the drain if you don’t have any outside plants to share it with. It is easy to unbalance the nitrogen ratio of an ecosystem when water is dumped outside and flows into a creek.
Are hydroponic plants as healthy as traditionally grown food?
They can be! It’s all about nailing the nutrient balances. The outside soil doesn’t contain any mysterious element that makes plants grown traditionally have more or less nutrition than those grown hydroponically. The same applies to flavor. A hydroponically grown fruit can taste just as good as a traditional farm-grown one.
Further, since hydroponically grown plants are free of pesticides and other potentially harmful chemicals, you can rest assured they would not have been subjected to them if they were grown outdoors.