How To Prepare Coco Coir For Hydroponics

by Lettuce Be | Last Updated: 07/22/2021

Growers are becoming aware that coco coir media needs to be buffered as buffering supplements are being sold worldwide. In today’s post, we’ll dig deeper into why it has such a significant impact on hydroponic gardening.

Coconut-related industries produce coir products as a by-product. Coconut husk makes up the raw material, and it comes from plantations that grow Coconut trees, mostly in tropical and sub-tropical areas.

There are several grading processes that classic ground coconut coir undergoes to attain the desired size and grade, including washing, buffering, drying, grinding, and compressing. The coco coir medium is altered in chemical and physical properties through this process, ensuring that it is the best coco fiber to grow plants in. You may ask – why bother buffering coco to prepare it for optimal plant growth at all? Would coconut coir mixes be worth the effort? Isn’t it just easier to use another hydroponic grow medium?

coco coir preparation for hydroponicsThese reasons explain why:

Positively charged ions such as cations (organic matter and coco) are attracted to their negative charges. Cation Exchange Capacity or CEC denotes the number of cations that something can hold or exchange. Therefore, CEC allows us to determine the amount of nutrients that the media can retain before it starts leaching. In Coco Coir, the CEC ranges from 40 to 100meq/100g (meq stands for milliequivalent). Coco can hold on to quality nutrients, but it can also lock them out, resulting in deficiencies in your plant that will show up in various ways.

Most coconut plantations are abundant along the coast because coconut trees are naturally tolerant of salt (sodium chloride). The naturally saturated cation exchange sites in coco are therefore saturated with sodium. A substantial amount of Potassium is also naturally present in Coco Coir’s CEC, while Calcium and Magnesium are contained in low amounts. During buffering coco, these are the most important cations.

Coco Coir initially has an electrical conductivity level between 2 and 6 MS/cm, which is excessive for cultivation. When washing Coco Coir, make sure that the EC is below 1mS/cm. It is only through buffering that You can remove Sodium and Potassium from the brown fibers after washing. Coco can be washed and buffered in different ways. If the Coco Coir is washed, you can remove the water-soluble elements, but you will remove the natural cation exchange fibers if the coco is buffered.

The goal is to lessen the number of CEC sites that contain Potassium and magnesium. A potassium atom can attach itself to up to 40% of sites and a sodium atom to up to 15%. This is very important. If Potassium accounts for 40% of the exchange, then there is 400meq of this molecule for every 100g of media. For every 1kg of compressed, dry Coco Coir, 12-15L of hydrated Coco Coir should be generated. The amount of Potassium contained in 100g of media may not seem like much, but it amounts to 15.6g. The 1.56g of Potassium in this feed is equivalent to the 0.22g of Potassium (220ppm) found in more balanced nutrient uptake.

Buffering Coco Coir

For growers with recirculating systems, buffering is especially useful since it gives them more control over how much calcium their plants receive and prevents salt build-up. In buffering Coco Coir, high levels of the elements we want, Calcium and Magnesium, are exposed to a solution containing calcium and magnesium in high concentration. As long as your coconut coir product is already bonded to sites, it is very difficult to remove unwanted cations and therefore, a simple washing will not work much to change their nature. Washing the quality coco coir only changes the EC, not the CEC.

Even if they are introduced into a solution simultaneously, the plant will absorb sodium, magnesium, potassium, and calcium at different rates. Sodium and potassium, which have single positive charges, are taken up more slowly by calcium and magnesium because they have a double-positive charge. The performance of buffering products that contain high calcium and magnesium levels is slower. Still, they allow the exchange to have lower sodium and potassium percentage while offering beneficial magnesium to the CEC. By doing this, you ensure that any nutrient mixes you use go directly to the plant instead of affecting coco’s CEC. This makes it a completely nutrient-neutral medium for healthy plant roots.

As a root binder and releaser of additional nutrients, coconut coir fiber acts like peat, as well as a moisture-holding inner substrate, like Rockwool. For the plants, coconut coir bricks act as a water and nutrient reservoir. Buffering can work in several ways. A water buffer, a pH buffer, a nutrient buffer, and a coco buffer are all types of buffers.

The Differences

The water buffer allows Rockwool to hold 92 percent of its volume in water at a time. This water supply is available to plants when they need it, and it is referred to as a water buffer. Coco coir discs can also be used as a water buffer. It holds 66% less water than Rockwool, but plain water is readily available to the plants.

The next item is a pH buffer since a potting mix is made up of acidic peats, and lime can neutralize this acidity. A lime buffer will neutralize outdoor plants if you water them with a non-neutral pH solution. The coco peat will stay wet for as long as the lime in it lasts. Potting mixes can correct any mistakes that growers make. Coco’s pH is neutral so that it won’t alkalinize the nutrient solution so that you can control pH values much better in coco coir bricks, but it is less forgiving than potting methods.

Additionally, peat or mineral soil is a nutrient buffer because they combine essential nutrients with charge sites. As previously mentioned, these are cation exchange sites. Hydroponic nutrients will be released later by soil fibers. You can provide plants with all elements in a specific ratio. The spaces between the fibers of coconut are similar. Potassium and sodium are already present in these. In addition to washing the coco with low EC water, you must also remove excess sodium and potassium.

Last but not least, there is the coco buffer. As mentioned previously, coco fibers also contain Potassium. The fibers will remove calcium and magnesium from the nutrient solution if calcium and magnesium cannot pull the potassium out. The coco is buffered, but it will always bind some calcium and magnesium in solution, releasing potassium. In addition to using potassium for generative purposes, the coco substrate also uses it. Considering that coco substrates absorb a lot of fresh water and do not require large amounts of water, it is possible to produce this exchange within a reasonable time.

Here are some how-to-steps on preparing and buffering your coco:

Healthy plant growth depends heavily on calcium, and the element is vital to nearly every aspect. Pay attention to your plant’s symptoms of nutrient deficiency. New leaves might appear crinkled and distorted, while dead spots may appear where the leaves turn brown and die.

Horticultural coir is mostly washed these days but not always nutrient buffered for hydroponics systems. Coco coir serves as a viable hydroponics alternative to expanded clay pebbles or clay pellets due primarily to its inertness as a growing medium.