Buffering Coco Coir


Two hands grabbing coco coir in a blue pot

Coco coir is a premium growing medium that has exploded in popularity for traditional soil-based mediums and hydroponic systems. Recognized for its high level of water retention and its environmentally friendly procurement (coco coir is harvested from coconut waste products), coconut coir has found a place in gardens and greenhouses across the globe.

However, if you’re looking to start using coco coir as a growing medium, you’ve probably noticed that you need to do something called buffering before coco coir is usable. If you’re trying to figure out what buffering is all about, read on. We’re going to cover the what, why, when, and how of coco coir buffering.

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What does it mean to buffer coco coir?

If you’ve read an article that talks about cation exchange, and uses the word “buffering” in every sentence, the process of buffering can seem intimidating. In reality, buffering is extremely simple. Buffering is the process of rinsing hydrated coir with calcium-magnesium water to prepare it for use as a growth medium.

We’re going to put the science on hold and jump into the “when” and “how” parts of coco coir buffering.

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When do you need to buffer coco coir?

If you purchase a compressed brick of coco coir, you will likely need to buffer it. If you purchase a bag of loose, ready-to-use coco coir, it may be pre-buffered. Sometimes coco coir is pre-buffered, but the package will likely indicate this. Plantonix Coco Bliss currently does not come buffered, but we'll likely be adding that to our catalogue in 2023.

Additionally, if you are adding Coco Bliss to an existing medium you may not need to buffer. For instance if you are mixing coco coir with compost or Worm Bliss there may be enough calcium and magnesium to handle it.

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How do you buffer coco coir?

Follow these steps to successfully buffer a condensed brick of coco coir. 

  1. Prepare two containers. One should have drainage holes drilled into the bottom. The other should be unmodified. We recommend using paint buckets since they can be easily lifted, though any form of container is fine. 
  2. Place the brick of coco coir into the unmodified container. 
  3. Dump water onto the coir to expand it. Generally, you want a gallon of water per kilogram of coir. 
  4. Wait 15-30 minutes. The coco coir will absorb water during this time. 
  5. Dump the coco coir into the drainage container. Once the excess water drains, the coir left behind should be fluffy. 
  6. Add water blended with calcium and magnesium nutrients into the drainage bucket with the coco coir. A good starting point is every 100 grams of coco coir needs about 2 grams of calcium and .5 grams of magnesium. This is the step that is referred to as buffering. You can also combine steps 3 through 7 if you want to save some time.
  7. Let it sit for 8-12 hours, then drain the calcium-magnesium water. This will give it enough time to remove the excess sodium and potassium.

Illustration of a farmer using coco coir in hydroponics

How to use coco coir for hydroponics?

Hydroponics enthusiasts seeking a sustainable and effective growing medium should look no further than coco coir. Derived from the fibrous husk of coconuts, this versatile substrate offers a plethora of benefits for hydroponic systems.

Prior to use, ensure the coir is properly rinsed and buffered to remove excess salts and achieve an optimal pH level. When setting up your hydroponic system, coco coir can be used in various forms – from coco coir bricks to loose coco coir fibers.

Its exceptional water retention and aeration properties create an ideal environment for root growth. Remember to regularly monitor the moisture levels and nutrient content, as coco coir allows for precise control over feeding cycles.

Whether you're a seasoned hydroponic gardener or a beginner, integrating coco coir into your setup can lead to healthier plants, higher yields, and an environmentally conscious approach to cultivation.

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Why do you need to buffer coco coir?

Lots of potassium ions are found in coco coir. When calcium and magnesium are introduced to coco coir, these nutrients replace sodium and potassium. The potassium loses its bond to the coco coir while the calcium and magnesium never reach the plant roots.

Rinsing the coco coir with calcium-magnesium before using it as a growing medium establishes a state of equilibrium. Since the coir already has the calcium and magnesium molecules it wants, it doesn’t steal them from the nutrients you’re providing your plants.

Don’t let the extra step of buffering dissuade you from using coco coir for your grow operation. Once buffered, coco coir is an incredible growing medium that boasts outstanding water retention, a neutral pH, and is green and cost-effective to produce, which results in an affordable shelf price.

Now that you know what it means to buffer coco coir, grab a brick and try it out today! 


  • Brenton

    Don’t want to bite off more than I can chew I would like to know best nutrients for coco coir and how to catch the run off. Thanks guys

  • Brenton Barajas

    Do you just add three to five units or tbs to one brick and just let it soak? And how many bricks of coco coir to do 10 to 12 plants and are their certain nutrients used for coco coir? And how do you catch the run off family? Very interested in this want to grow one half the tent dwc and the other half of the tent coco coir. Do you have feed charts to give? And what’s the best nutrients for coco coir thank goodness for you 🙏 thank you

  • Ellen Fraser

    I have purchased a block of your Coco coir but did not know this!
    Please let me know where to get the correcting ingredients! And what product names you recommend?

  • Judy

    I have been using coir for some time now, and not ONCE have I heard about buffering ! Thank you for this tutorial- i expect to see a difference in my little green ones.

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