When it comes to growing mediums, hydroponics is second only to soil. Before getting into the nitty-gritty of fertilizers, specifically which one you are going to use, know that your hands are tied when growing cannabis in hydroponics. And no, it is not a bad thing at all. For you to understand and have a deeper appreciation of how they work, then we are going to take a look at the two most commonly discussed types, and which one you will use.
Should I Use Mineral or Organic Fertilizers for Hydroponics?
So much has been said about the benefits or ill-effects of using mineral fertilizers – as opposed to organic. You could be on one side and spend the rest of the day arguing about its merits and never reach a consensus. Come to think about it, healthy debate is highly educational – but it does have a repercussion on the growth of plants. But to answer the question, you are going to use a form of mineral fertilizers when growing cannabis in hydroponics.
Organic fertilizers, which some might think of as the “gold standard of fertilizers”, comprise a variety of plant-derived materials, animal manures, and agricultural by-products. They rely on healthy soil microbial life to decompose, leaving nutrients for the plants to absorb. Because the rate of decay takes time (and popularly called slow-release), there is practically no risk of overdosing.
But there is only one problem – the beneficial microbes needed to “convert” organic matters into plant-usable nutrients only live in soil mediums. In other words, this type of fertilizer is not suitable for hydroponics.
You are left with mineral fertilizers, also referred to as synthetic or chemical fertilizers.
But aren’t many people talking about how destructive it is to the environment?
As alluded to earlier, there are arguments for and against the use of mineral fertilizers. The funny thing is, even if the opposing sides were to engage in an “all-out war” debating the pros and cons, the plants do not care. On a molecular level, the nutrients absorbed and used by the plants are one and the same. It is, in fact, a misconception that organic fertilizers are better than mineral fertilizers. Once the microbes break down organic matter, they leave nutrients that are the same as what mineral fertilizers provide.
Can I Use Fixed Fertilizers with Hydroponics?
About 90% of mineral fertilizers applied to plants are solids. They typically come in fixed or granulated form. A simple explanation of the difference between these two is as follows:
- Fixed fertilizers are concentrated. They can be dissolved in water and irrigated into the medium or foliar-sprayed on the leaves.
- Granulated fertilizers are broadcast by hand and scratched into the medium. Upon coming into contact with water, they slowly release nutrients for the roots to absorb.
In hydroponics, you are feeding the plants directly, not like feeding marijuana plants in soil. Granulated fertilizers, in this case, are not suitable. As for fixed fertilizers, you might think that it is possible to dissolve them in the nutrient solution. Unfortunately, they are not soluble enough.
To answer the question, no. You cannot use fixed fertilizers for hydroponic cannabis growing.
What Kind of Fertilizer Can You Use for Cannabis Growing in Hydroponics?
It seems at this point that you are out of options. But remember, 90% of mineral fertilizers are solids. There is still the remaining 10% – liquids, and that is the most viable type of fertilizer to use. As you are about to find out, they are ideally suited for directly feeding the plants through their root system.
Remember that plants do not distinguish between the source of nutrients – mineral or organic. In the same manner, they also cannot differentiate between fixed or liquid fertilizers. Both, of course, have their advantages and disadvantages. In the end, they will still fulfill their job description – nourish the plants.
Liquid fertilizers are the most suited for hydroponic marijuana growing application, because:
- Not all minerals are the same. Phosphorus, for example, is not as mobile as others. They remain where the granule containing them is, unlike when in liquid form.
- Liquid fertilizers are not as “hot” as fixed fertilizers. Just the same, they can provide all the essential nutrients with less risk of burning the plants.
- Fixed and granulated fertilizers are not as precise as liquid fertilizers in their nutrient composition.
- Liquid fertilizers are superior with regards to ease of preparation and use.
- Once again, liquid fertilizers are soluble enough that it is easy for the plants to absorb them – much more so than dissolving fixed fertilizers.
Use Liquid Fertilizers – Not Fixed – for Cannabis Growing in Hydro
Sourcing fertilizers – regardless of which type – should be limited to reputable brands with a history of providing high-quality products. As to the specific type, that will depend on the growing system and medium.
For soil mediums, you have the option of using chemicals or organic. Most people do choose to use organic matter and keep the root zone teeming with beneficial microbes. Some people even think that the buds grown from organically grown cannabis plants have a better terpene profile, resulting in more appealing tastes and smells.
However, that may not be an option when it comes to hydroponics. With chemical fertilizers, fixed or granulated fertilizers are also not suitable. Even if you could dissolve fixed fertilizers, for example, in a water solution, they are not soluble enough that the plants could absorb them efficiently. As a result, there are more residues left in the nutrient solution, which may cause problems later.
Liquid fertilizers are the best way to go. They are not at all difficult to prepare and use. Not only are they excellent starters, but you can also make adjustments later easily.
Explosive growth is the hallmark of growing in hydroponics. The results speak for themselves – liquid fertilizers work – not fixed, and certainly not granulated fertilizers.