How to Buffer Coco for Growing Cannabis

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In this guide, we will explain how to buffer coco for growing cannabis. The whole process is reasonably easy and it will not take that long. Buffering coco is a great way to clean it, and bring it to the correct EC and pH levels before using it. This can help get your plants off to the best start in their new medium.

Why You Should Buffer Coco for Growing Cannabis

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The reason for buffer coco before using it to grow cannabis can be complex. Essentially, coco is a medium that is void of nutrients. This means it has none, or very little nutrients in it that are useful to cannabis growing. You have to add them all. 

Some nutrients, particularly calcium and magnesium, will be “leached” from your nutrient solution, and absorbed by your coco. As a result, your plant will not get the calcium and magnesium you’re feeding it, it is being absorbed by coco instead. 

To prevent this, coco is buffered. Coco is left soaking in a nutrient rich solution of Cal/Mag for a while. This allows the coco to absorb as much calcium and magnesium as it can hold and release any sodium ions it has. As a result , calcium and magnesium will not be taken from your plant and sodium won’t be released to the roots.

Does All Coco Need to be Buffered?

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No. If you buy a bag of loose coco, from a reputable brand like CANNA, or Plagron, it will already be buffered. Buffering is more for coco that is either in a compressed brick, or being reused from an old grow. 

If you’re unsure, then consider buffering the coco anyway. It does not take very long, and it can correct the pH level and nutrient level of the coco before plants go into it. 

What Equipment do you Need to Buffer Coco

To buffer coco for growing cannabis, you will of course need a brick of compressed coco, or coco you intended to reuse. A compressed coco brick will expand when it comes into contact with water. So you need some big buckets or containers. 

This is best done outside or where you have plenty of space, and can risk a spillage. Here is a list of items you will need:

Items List

  • Two 18 Gallon (63L) Plastic Tub
  • A strainer or colander with 2-3 mm holes
  • Cleaning equipment ( Gloves, Sponge and H2O2)
  • Cal/Mag
  • Coco Grow Nutrients
  • Lots of Water

It would be a good idea for you to have your pots prepared and ready for the coco to go into them too. The better prepared you are for the whole process, the easier it will be. 

How to Buffer Coco

Clean the Containers 

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Clean the containers with a weak H2O2 solution. You may use a small amount of bleach instead. The whole idea of this part of the process is to remove bacteria or fungi from the containers. This will prevent them from getting into the coco and onto your plants. 

After everything is clean, rinse off the bleach or H2o2 from the containers. Now you’re ready for step 2. 

Filling Container with Water

Take the 18 gallon container that has no holes in it and fill it with 15 gallons of water. Of course, if you are using a different sized container, you won’t use the same amount. Instead fill the container around ¾ of the way. Just leave enough room for the coco to fit in it without spilling.  

Add the Coco to the Water

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Next you should add the coco to the water. If you’re using a compress brick, it will take sometime before the coco is fully broken up. Leave the brick to soak for 30 minutes. When you return, check to see if it is completely soaked and broken up. If not, break it up a little more, and wait 15 more minutes. 

Whilst you wait, any salt or sediments will be broken down from inside the coco. They will either sink to the bottom of the container, or dissolve into the water. 

After around 45 minutes, the coco should be fully saturated. The good stuff will be floating at the top, and the sand and sediments will be at the bottom. 

If you are recycling your coco from a previous grow this section isn’t done as the coco is already hydrated. It is useful when reusing coco to remove as much old root material from the coco. Once this is done your used coco can begin the re-buffering process here in the next step.

Draining and Rinsing the Coco 

Now you need to drain and rinse the hydrated coco. To do this, fill your colander/strainer with wet coco and let the water drain. Next use running water to flush out the superfine particles out of the coco. These particles hold more water that you really want and can restrict the flow of oxygen to the roots.

You will see some fine particles drain from the coco. The bigger fibres are the most desirable ones. When done, drain and put into the empty bucket. Continue until all the hydrated coco has been washed and drained.

The next step is to actually buffer the coco. 

Buffering The Coco

Now you have clean fresh coco. To buffer coco for growing cannabis you need to add some Cal/Mag to it. For this you should use any good Cal/Mag supplement. It will have plenty of calcium and magnesium in it to release the sodium from the coco. 

Mixing the Nutrients for Buffering Coco

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In an empty bucket, mix a solution of Cal/Mag for buffering. You should use 1.5 times the amount the manufacturer recommends to do this. The EC of the buffering solution will be high, sometimes as high as 1.3 to 2.1. The idea here is to soak the clean coco so it absorbs everything it needs from the Cal/Mag solution. 

Add the nutrients to the water and stir them well! Let the nutrients sit for a few minutes and then check the pH. The pH should sit between 5.8 and 6.2. If it is not within this range, adjust it. 

Soaking the Coco

Pour the Cal/Mag solution into the bucket of coco. Let the coco soak in the solution for about 8 hours or more. After it has soaked, drain the coco and mix a new bucket of Cal/Mag at the same concentration as the first one.

Pour the second Cal/Mag solution into the bucket of drained coco and let it soak for 8 hours again. Then simply drain the solution from the coco. The coco is now buffered, you just have to prepare it for you plants to be planted into.

Rinsing the Coco

To prevent burning your plants, the coco now must be rinsed free from the high EC of the buffering solution. Then it is loaded with a light dose of grow nutrients. Place the coco into your pots. Mix a light grow nutrient solution at about 1/4 the manufactures recommended dose and take an EC reading of that solution. This is your runoff target for rinsing/flushing out your buffered coco.

Run plain water at pH 5.8 through the pot until the runoff is at the same EC level or lower as the nutrient solution you just mixed. After the runoff stops, water the coco thoroughly with the grow nutrient solution allowing for reasonable runoff. This will ensure your seedlings will have some food available to begin their life. That’s how you buffer coco for growing cannabis

To Summarize

The whole process is easy, and it is massively beneficial to your plants. The calcium you now give to your plants everyday will go to your plants, and not be leached into the coco. This will give you a much healthier happier cannabis plant for the whole grow cycle. Simply follow this guide and your coco is buffered and ready for use. 

From here you can put it into your garden, and plant your seedlings or clones into it. Just plant your plants, feed them with your usual feed and they will love their new coco. 

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