How Often Do You Feed a Hydroponics System?
There are two rules that you can adapt for introducing a new feed or fertilizer to your hydroponics feeding system.
The first and more oft-followed rule is that the reservoir should be emptied and refilled after a maximum of ten days. However, a ten-day interval only occurs in extreme cases; in general, though, the reservoir emptying and refilling occurs after every five to eight days.
The next method is called the ‘50% method’, and is slightly more flexible than the first one. In this method, the farmer will measure the reservoir level when the reservoir is first filled, and note down the number of gallons of water. Then, the water levels are measured every two days, and any reduction in water is compensated for using plain water. Once the farmer has replaced 50% of the initial amount of water, they will stop topping up their tank and let the solution level go down until it reaches the top of the water pump.
Once this happens, the farmer will drain and clean their tank, and then put in a new batch of fertilizers or nutrients.
Learn more about Hydroponics Feeding Systems and how they works.
In what Order do I Add General Hydroponic Nutrients?
For a hydroponics feeding, you will need the following three mixes for the fertilizer:
- A mixture of Nitrogen, Potassium, and Phosphorus (NPK Mix)
- Magnesium sulfate (Epsom salt)
- Calcium nitrate
The crops will obtain carbon, hydrogen, and oxygen through the surrounding air and water. Hence, in general, you do not need to worry about these three elements.
The remaining three primary hydroponic nutrients are nitrogen, potassium, and phosphorus, all of which will be provided through the NPK mix.
The secondary hydroponics nutrients are sulfur, magnesium, and calcium, and this is where Epsom salt (magnesium sulfate) comes into the picture, as it offers both sulfur and magnesium.
The next thing you want to deal with is the micronutrients. Some large-scale hydroponics farmers do purchase auto-dosing systems for micronutrients. However, for the most part, micronutrient deficiencies should be treated as and when they manifest in your plants.
As far as mixing the nutrients go, being familiar with your feeding system will be your biggest advantage.
Often, practitioners go for the mixing tank or sump, since it offers turbulence – for effective mixing, it is imperative that your plants have sufficient room and turbulence. Hence, you need to find a section in your system that provides this combination of turbulence and space.
There are two ways to mix the nutrients together. You can mix all the three nutrients and then add them to the tank as a mixture, or you can add each of the nutrients separately. Regardless of the approach you choose, remember to never mix calcium nitrate with anything else, since it is incompatible with the other parts of your nutrient solution.
To learn the amounts of nutrients that you should add, refer to the nutrient mix label and follow the given instructions. The required quantities for all nutrients, including the Epsom salt, will be mentioned on that label.
Can You Reuse Hydroponic Water?
Reusing your hydroponic water is the simplest way to dispose of it, and this is what a lot of hobby growers and small-scale farmers do.
There are three main ways through which you can sterilize hydroponic water: UV Disinfection, Ozone Sterilization, and Pasteurization.
1. UV Disinfection:
UV disinfection is a highly effective method of reusing hydroponic water. Since it is chemical-free, this method is extremely desirable for hydroponics farmers who want to keep things natural.
This method makes use of high-pressure UV lamps present inside a radiation chamber. The water passes through this chamber, and the UV lamps get rid of any bacteria or harmful pathogens present in the water. New York’s Catskill-Delaware Water Ultraviolet Disinfection facility relies upon UV disinfection to sterilize water for the residents of New York, USA.
Compared to the other two sterilization methods, UV disinfection is immensely cost-effective. Besides, this approach is fully natural and does not create any undesirable by-products. The drawback, however, is that UV sterilization fails to neutralize any inorganic compounds, chemical contaminants, or dissolved organics found in water. This means that this approach is unsuccessful at getting rid of salts, heavy metals, or chlorine (although chlorine can be removed through photolysis, the process requires very large UV doses and is generally not viable).
2. Ozone Sterilization:
The second method is ozone sterilization, which involves infusing ozone into the water. Ozone is a natural gas created by the sun’s UV radiations and can be found in the earth’s ozone layer. Ozone can also be created artificially for various purposes, one of which includes the sterilization of hydroponic water.
Ozone generators are used to produce ozone gas. There are two types of ozone generators – ultraviolet and corona discharge – both of which create ozone by splitting oxygen molecules into oxygen atoms. The singular atoms then combine with the oxygen molecules and lead to the production of ozone. This ozone gas is then infused into the hydroponic water to get rid of germs or contaminants.
Ozone sterilization is highly effective and takes very little time to eliminate contaminants present in the water. Other than that, ozone is environmentally friendly, and, when used in the growing room, can help protect your plants against many types of diseases and pests (including mites and spiders). The downside is that ozone sterilization does not come cheap. Moreover, ozone is highly corrosive, and, if used improperly, can cause severe damage to your system equipment.
3. Pasteurization:
The third approach to sterilizing hydroponic water is called pasteurization and makes use of heat. Pasteurization is often associated with the dairy industry, where the process is used to purify milk. However, this method can be applied to hydroponic water as well as a number of other liquids.
The process involves rapid heating of the water, using heat exchangers. These exchangers, as the name suggests, trade temperatures between two gases or fluids. To make it short, this heat exchanger uses a liquid or gas to cool or heat the water present in a hydroponics feeding system.
A major benefit of pasteurization is that the water need not be pre-filtered. Other than that, you can also reduce the accumulation of biological agents such as minerals, in the water. Unfortunately, these agents end up accumulating inside the pasteurization machine/heat exchanger. Therefore, to prevent excessive buildup, the machine needs to be regularly and thoroughly cleaned.
Next, we will briefly highlight the advantages and disadvantages associated with each sterilization method:
| System | Advantages | Disadvantages |
| UV Disinfection | Cost-effective; free of chemicals; immensely effective | Unable to get rid of chlorine, salts, or heavy metals |
| Ozone Sterilization | A most effective method of sterilizing water; prevents disease; environmentally friendly | Very corrosive (can damage equipment); expensive |
| Pasteurization | No need to pre-filter the water; reduces mineral buildup in water | Can cause mineral buildup inside the pasteurizing machine |
Do General Hydroponics Nutrients Expire?
Even though hydroponic nutrients do not exactly expire or go bad, they will eventually lose their efficacy – even with proper storage.
Generally, a hydroponic nutrient solution can go anywhere between a few months to one or two years before needing to be replaced.
A good way to determine if you need to replace the nutrients is by checking the pH level of the tank water and then consulting the nutrient package label to see how often the nutrients need to be added to the water.
If your nutrient package has been in storage for over one year, you should consider buying a replacement batch.
Liquid hydroponics nutrients will generally have a shelf life of one to two years. In other words, this is the period during which the nutrients are most effective. If retained beyond this period, the nutrients might degrade to a point where they might not have any effect on your plants.
Another thing to note is that this shelf-life is not counted from the day that you purchase the product. Instead, the nutrients’ shelf life commences once all the nutrients have been mixed together. For instance, if your concentrated nutrients are residing in an open container and you decide to transfer them into another, larger container, this transfer will not reset or prolong the nutrients’ shelf life in any way. In other words, the nutrients will be good for two years from the day that they were mixed – not from the day on which they were transferred to a different container.
Can I Use General Hydroponics Nutrients in Soil?
Yes, you can certainly use General Hydroponics in your soil. All General Hydroponics nutrient blends possess the elements that are essential for plant growth. You should start with the formula ratios mentioned on the label for the particular crop or plant that you want to grow. Once you feel comfortable, you can start conducting trial-and-error experiments until you land on the formula that is in line with your specific requirements.
Final Word About Hydroponics Feeding System
To sum up, this guide attempted to cover some of the most essential information and questions surrounding the General Hydroponics feeding schedule. To learn more about hydroponic farming, please feel free to check out some of the other blogs on our website.
