Interesting little tidbit from AN, before they start into their pH Perfect sales pitch:
How The Chelation Process Facilitates Better Plant Performance
If you’ve been growing with hydroponics or soil for a while, you’ve probably heard the terms “chelate,” “chelated nutrients” or “chelating agent.” However, you may be unsure of what these terms mean — or how chelation can help you grow better performing, higher quality plants.
Chelation 101: What Are Chelates?
In its simplest definition, a chelate is a compound that is bonded to a metal atom at two or more points. But what exactly does that mean — and what does it have to do with growing crops?
The word “chelate” — pronounced “KEY-late” — is derived from the Greek word for “claw.” Understanding this, the word’s definition becomes a little clearer: The chelate bonds itself to a metal atom in a clawlike fashion.
As it relates to growing, a chelate is an agent that bonds to a micronutrient, thereby making the micronutrient more readily available for uptake in plant cells.
Let’s unpack this concept a little more.
The Chelation Process
Most growers know about the three major nutrients that plants need: potassium, phosphorus and nitrogen. But many novice growers don’t realize that plants also need other nutrients, like iron, zinc and magnesium. Because they are needed in relatively high quantities, potassium, phosphorus and nitrogen are referred to as macronutrients.
Your plants need lower quantities of elements like iron, sulfur and calcium, so we refer to them as micronutrients. While they’re not needed in the same quantities as macronutrients, micronutrients are every bit as vital to your crop’s diet and healthy growth.
The problem is that most of those necessary micronutrients are unavailable to your plants while in their basic form, because metals like iron and zinc have a positive charge, and the pores on your plants wherein the metals would enter have a negative charge. The positively charged micronutrients cannot enter through the negatively charged pores.
This is where chelates come into play.
When a chelate bonds to a micronutrient, it surrounds or encapsulates individual ions and gives them a negative or neutral charge, allowing the nutrient to enter through the negatively charged pore and travel into the plant’s tissues.
Chelation isn’t a phenomenon limited to plants; many of the nutrients and minerals humans ingest are chelated.
Chelating Agents In Hydroponic Solutions
Now that we have a basic understanding of what chelates are and how they enable micronutrient uptake in your plants, let’s look at chelating agents in hydroponic solutions and pH levels.
There are several types of synthetic chelators used in hydroponic grow nutrients, including:
- Ethylenediaminetetraacetate (EDTA)
- Diethylenetriaminepentaacetate (DTPA)
- Ethylenediaminedihydroxy-phenylaceticacid (EDDHA)
There are also several naturally occurring chelating agents. The three most often used in grow nutrients are fulvic acid, humic acid and amino acids. Fulvic acid is soluble in all pH ranges, while humic acid is soluble in a pH range of 6.0 and above.
Amino acids are most effective in pH ranges of 5.0–7.5.
Similarly, EDTA is better suited to pH levels of 7.0 and under, while DTPA works better in higher pH ranges. EDDHA can function well in both high-pH and low-pH environments.
The different types of chelates also vary in the way they function in your hydroponic garden.
Synthetic chelates — EDTA, DTPA and EDDHA — only stay bound to the micronutrient ions until the point at which they enter your plants’ cells. Once this occurs, the plant unbinds the chelator from the nutrient and releases it back into the hydroponic solution, where it becomes free to chelate another nutrient and escort it into the plant for absorption.
The same concept is true of natural chelators. Fulvic and humic acids are not absorbed into the plant — they are released upon escorting the micronutrient ions into the plant. However, amino acids are absorbed via plant tissues, which is why it’s important to have a range of chelators in your grow; if the plant gets too full of amino acids, it may not have room to absorb all the micronutrients it needs to thrive.
1 of Mega, Cal-Mag, and Silica for hydro. The Silica just wants to drive the pH up and out of the optimal range for that type of growing.
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