Prior to any treatment, coco coir’s cation exchange complex is naturally saturated with sodium due to coconut trees natural proximity to coastal areas and high tolerance for salt (sodium chloride). Coco coir’s initial salt content, measured by the electrical conductivity (EC), can range between 2 and 6 mS/cm – excessive for plant growing. Coco coir’s cation exchange complex also naturally contains large amounts of potassium, which competes with magnesium and calcium for uptake. Char Coir coco is abundantly washed with fresh water until reaching an EC below 1.0mS/cm (based on 1:1.5 extraction method). Even after washing, coco coir still contains residual sodium and potassium left in the complex, which can lead to nutrient lock up later. To stabilize the cation exchange complex and avoid nutrient deficiencies during the crop season, adequate buffering of coco coir is essential.

Buffering Process and Quality Standards

Washing and buffering are different processes that accomplish different goals. While washing removes only elements that are soluble in water, buffering also removes elements which are naturally bound to the cation exchange complex.

During the buffering process, coco coir’s cation exchange complex is saturated with a solution of calcium nitrate for an extended period. The absorbed calcium displaces the residual potassium and sodium in the complex, which is washed away. According to Dutch RHP certification standards for coco substrates, buffered coco coir should contain less than 1 mmol sodium and less than 2 mmol potassium. The buffering process also reduces problems with nitrogen draw-down that would occur in non-buffered coco peat.


Why Buffering Matters

Buffering is especially important for growers who want to apply calcium and magnesium to their crops and/or growers who recirculate their drainage water. It provides more control over the amount of calcium provided to the crop and prevents excessive accumulation of salts if not draining to waste.

If the coco coir cation exchange complex is not buffered, the positively charged cations applied to the plants, such as calcium and magnesium, will have a stronger attraction to the coco complex and become unavailable to plants (nutrient lockup), while potassium and sodium, less attached to the complex, will be displaced, come into solution and be taken up by the plant instead of calcium. This leads to all sorts of crop problems – from excessive salt uptake by roots to calcium deficiencies, which is something growers wish to avoid at all cost.

Calcium is a crucial regulator for plant’s growth and is involved in nearly all aspects of plant development. Some of the most noticeable signs of calcium deficiencies tend to appear on new, upper leaves and include dead spots, crinkling, spotting and mottling, small brownish spots, stunted growth, small and distorted new leaves, curled tips, leaf die-off, etc. Clearly not a situation a grower wants!

Buffering coco prevents all this since in buffered coco coir, the cation exchange sites have already been occupied by calcium while sodium and potassium have been washed away. Most coco coir being sold today is washed, but not all coco coir is nutrient buffered. Clean, buffered Char Coir coco is the choice for any grower who wants healthy happy plants that reach their full potential.

Cocopeat is shipped in compressed form to reduce transport and handling costs. Converting cocopeat blocks to coir dust is easy. All you need to do is add water to the block and the block will puff up into moist fluffy cocopeat. Just add sufficient water to the block to make sufficient quantity of moist cocopeat. You can put away the unexpanded block for later use.

If you need to expand the whole block, immerse the block in a large tub capable of holding at least 25 litres of water. Remove the wet expanded cocopeat that floats in the water, while continuing to add water to the tub till the complete block is expanded.

If you are a large grower who needs to expand large number of cocopeat blocks, place the cocopeat blocks vertically with a distance of about 1 feet between them. Spray water from a hose on the cocopeat blocks while working on the blocks with hand to expand them into moist cocopeat. Another method is to use machinery to crush the block into powder and then use the dust.

If you are using low compression cocopeat for absorption purposes, you can simply break and crush the block into powder in the palm of your hand.

Using cocopeat for potting mix: Mix the expanded cocopeat with leaf mould or homemade organic manure in the ratio of 1:1. Add red soil or sand in small quantities for large plants, otherwise the cocopeat will not be able to hold the weight of the plants as they grow. Red soil tends to compact over time (despite the cocopeat), so take care not to mix more than one third of the mix. For germination, mix cocopeat, leaf mould and sand in the ratio of 1:1:1. If you are using commercial organic manure, it would be better to mix cocopeat and organic manure in the ratio of 10:1 as commercial organic manures are often of high strength.

Using cocopeat as hydroponics medium: For hydroponics, it is better to thoroughly wash and buffer the cocopeat before use as most of the nutrient formula available on the web are not meant for growing in coir. First expand the cocopeat block as instructed earlier. Wash the expanded cocopeat in a large tub of soft water for a few minutes. Drain the water and repeat the process. If the cocopeat you bought is unwashed, you will have to repeat the process a couple of times more. Dissolve calcium nitrate (available in agri supply stores) in water in the ratio of 1 g per litre and allow the cocopeat to soak in the solution for 12 hours. Drain any remaining solution and wash the cocopeat again in soft water a couple of times. The cocopeat is now ready for use as a hydroponics medium.