01 · Direct answer
Choose the grade by the process the crop needs. Natural coir pith is unwashed and suits tolerant crops, landscaping and substrate manufacturers who correct EC in their own blend. Washed coir has been through freshwater cycles that remove the soluble salts. Buffered coco coir is washed and then treated with calcium or magnesium, which also displaces the sodium and potassium held in the pith, so growers of salt-sensitive crops such as strawberry, tomato, flowers and seed trays ask for it.[2]
| Grade | Process | Typical crops |
|---|---|---|
| Natural | Shredding and screening only, with no washing and no additives | Coffee, clonal eucalyptus, citrus, landscaping, leafy vegetables |
| Washed | Freshwater immersion and drainage, repeated until the drainage water reaches the target EC | Potted ornamentals, forestry seedlings, soilless vegetables |
| Buffered | Washed, then soaked in a calcium or magnesium solution and rinsed | Strawberry, tomato, flowers, orchids, seed sowing |
Grades: Natural (unwashed, no additives), from our plant in Paraipaba, Ceará. Buyers who need a lower EC wash or buffer the pith at their end. Tell us your crop, your EC method and target, your volume per month and your port.
02 · What washing removes and what it does not
Dry coconut husk carries potassium (1.60 %), chlorine (1.80 %) and sodium (0.38 %) in its own structure, which is why raw EC ranges from 0.4 to 6.0 mS/cm according to EMBRAPA.[1] These salts are not all in the same place, and that is what separates the grades:
- Chlorine and the salts dissolved in the pore water leave with fresh water. Chlorine, according to Romero, is the easiest to wash out.[2]
- The sodium and potassium held in coir's organic complex stay when only water is used, because "water alone does not have the capacity to displace" these ions. Calcium or magnesium does.[2]
- Romero describes four levels on the market, from unwashed and washed to super-washed and treated with calcium or magnesium, and advises buying coir "with a first name and a surname", where the first name is the particle size and the surname is the salt level.[2]
- The washing target cited by EMBRAPA for dry coconut husk is EC below 1.0 mS/cm.[1]
A lower starting point means fewer cycles. Our husk is dry mature husk, rain-aged inland and never retted in brackish water. The literature documents five or more freshwater cycles for high-salt retted material.[5] EC bands by crop are detailed in Coir pith EC by crop.
03 · How washed coco coir is made
- The tank receives fresh water until the pith is covered, and the water is measured before it goes in.
- The pith is soaked with agitation and then drained through a screen. The first water comes out dark because it carries tannins and dissolved salts.
- The EC of the drainage water is read in each cycle, and the cycle repeats with new fresh water until the reading reaches the target.
- The pith is pressed to remove excess water and then dried.
- Once dry, the material is measured in the 1:5 extract, and the value is stated with its test method.
04 · How buffered coco coir is made
- The full wash comes first, so that fresh water removes the soluble salts before calcium goes in.
- The washed pith is then soaked in a calcium nitrate solution, with agitation during the contact time.
- Calcium, with a +2 charge, occupies the exchange sites and displaces potassium and sodium, which move into the solution.[2]
- Rinses with fresh water carry away the displaced potassium and sodium, which would otherwise stay with the product.
- The pith is drained, pressed, dried and tested in the same 1:5 extract.
Two points from Romero matter to anyone who fertigates. The treatment uses calcium or magnesium, one of the two, and the calcium held in place of sodium and potassium is not available to the plant, so it does not count in the nutrient solution.[2] David Cadena describes well-prepared coir as a management buffer for EC and pH that synthetic substrates do not offer.[3]
05 · When Natural is the right choice
- Landscaping, mulch and bed cover, where the use tolerates a higher EC.
- Substrate manufacturers, who set an EC ceiling in the contract and correct EC in the final formulation. The husk's natural potassium is why they cut potassium in the blend.[1]
- Coffee, clonal eucalyptus, citrus and leafy vegetables, with a limit in the contract.
We sell Natural coir pith by volume, by the full truck in Brazil and by the full 40' HC for export, as a coir pith supplier. Terms for importers are on import coir from Brazil, and buyers of full loads can start at coco coir bulk and wholesale. Company data are on Company facts.
06 · Frequently asked questions
Is washed coir pith the same as buffered?
No. Washed coir goes through freshwater cycles. Buffered coir is washed and then soaked in a calcium or magnesium solution, which displaces the potassium and sodium held on coir's exchange sites. Both lower EC, and only buffering removes the salt that water cannot reach.
What does coco coir washed and buffered mean?
It means the pith was washed with fresh water and then buffered with calcium or magnesium. Washing removes the soluble salts, and buffering displaces the sodium and potassium held in the organic structure.
How many wash cycles does coir pith get?
It depends on the starting salt level. The EC of the drainage water is read in each cycle, and washing stops when it reaches the target. The literature documents five or more cycles for high-salt retted material.
Does washing remove all the salt from coir pith?
No. Water removes chlorine and the salts dissolved in the pore water, and the sodium and potassium held in coir's organic complex stay, according to Adalberto Romero. Only calcium or magnesium displaces them. This is why a washed lot can read a low EC and still hold a potassium reserve that appears weeks later, during fertigation.
Can I buy Natural coir pith and wash it myself?
Freshwater washing lowers EC, and the target cited by EMBRAPA is below 1.0 mS/cm. Washing on the farm does not buffer the pith, because without calcium or magnesium the sodium and potassium held in the organic structure stay there. For landscaping, substrate manufacturers and tolerant crops that does not matter, and for strawberry, flowers, orchids and seed sowing growers use a buffered grade.
Can I buy buffered coco coir bulk from Brazil?
Grades: Natural (unwashed, no additives), from our plant in Paraipaba, Ceará. Buyers who need a lower EC wash or buffer the pith at their end. Tell us your crop, your EC method and target, your volume per month and your port.
07 · Sources
- EMBRAPA Tabuleiros Costeiros, Comunicado Técnico 226 (COT-226-19): raw EC 0.4-6.0 mS/cm, washing target below 1.0 mS/cm, composition K 1.60 % / Cl 1.80 % / Na 0.38 % of dry husk.
- Ing. Adalberto Romero webinar (Science Fetti / El Semillero, Colombia, 2025): four salt levels, "first name and surname", water does not displace Na/K from the organic complex, Ca or Mg treatment (one of the two), bound calcium not available to the plant, chlorine as the easiest salt to wash out.
- Lic. David Cadena webinar (Mexico, hosted by Riego Rotoplas, 2026): coir as an EC and pH management buffer.
- Carve public specification: Coir Pith page (Natural grade).
- Raviv, M., Lieth, J.H. & Bar-Tal, A. (2019), Soilless Culture, 2nd ed., ch. 8 (five or more cycles for high-salt material).