Before starting a cannabis grow in coco, you should be properly prepared and informed on how the medium works. Coco is a great medium for growing cannabis, but there are a few things that can be overlooked by new growers that can cause problems. 

In this guide, we will go through everything you need to know before starting a cannabis grow in coco. We will take you step by step through the whole process of starting a grow. 

To begin, you should ensure you have good quality coco. This will come in a bag, or as a compressed brick.

Different types of Coco

There are two main types of coco. It will either come prepared and ready to use in a bag, or it will come as a compressed brick. You may need to treat compressed coco before using it to grow cannabis. 

Coco in a Bag

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Coco in a bag is the best option. When you buy coco in a bag, from a good supplier, it will come pre treated and will be ready to use straight out of the bag. 

You can easily find 50L bags of coco in most garden stores and grow shops. It is reasonably cheap and can be used over and over again! 

There are two brands that we would recommend when you are starting a cannabis grow in coco. They are CANNA and Plagron. Both of these brands of coco come pre-treated in a bag. Simply fill your pots with it, and prepare the coco. 

Coco in a Compressed Brick

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If you’re starting a cannabis growing coco using a compressed brick, it will need to be buffered before you use it. Compressed coco will hold a lot of salt, silt, and other contaminants that you do not want in your medium. 

It will need to be soaked, cleaned and buffered before you use it. This is not a difficult process, but it does take time. If you need to buffer your coco for growing cannabis, then you can find a guide right here:

How to Buffer Coco for Growing Cannabis 

When the coco is buffered and sitting in your pots, it is time to prepare it before you plant your plants into it.

Preparing Coco for Cannabis Plants

It is a good idea to start off using small pots, about 1 litre in volume. But the size of the starter pot is up to you. The bigger the pot is, the more water you will use for every feed. So starting in a small pot and transplanting as the plant grows is the preferred method. 

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Fill your pots with your coco. Coco is void of nutrients, and it will not feed your plants on its own. You have to add a small amount of nutrients to the medium (coco). 

To do this, you will mix a small amount of grow nutrients and water. The you will water your coco as if it had a plant in it. This gets the medium at the perfect level for your plants before they are planted. 


Mixing the Nutrients

Before planting your seedling or clone into coco, you need to make sure it is at the correct EC and pH. 

Take a look at the manufacturers recommended dosage. These nutrients are usually way overdosed for cannabis, as they are often made for growing vegetables and other plants. 

Cannabis doesn’t need a lot of nutrients, so we are going to start off very light. Use just ¼ of the recommended dosage and add this to some water. This is called a nutrient solution.

Note down the EC of the nutrient solution. Let’s say for example, it is 0.6 EC. Then, pH the nutrient solution to 5.8. 

What is EC?

EC stands for electro conductivity. By reading how easy electricity can pass through your nutrient solution, you can tell how many salts are dissolved in it. The more salts in the water, the higher the EC. 

Read more about EC, and how it works here:

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What is pH

Nutrients will only be available to cannabis plants at certain pH levels. If the pH of the feed or medium is not within the correct range, your plants will not eat not matter how much food is available to them.

Make sure the pH is always within range. Find a good pH meter here:

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Balancing the Coco

At this point, you are going to water the coco until water is coming out of the bottom of the pot. This water is called run off. You will collect the run off as it comes out of the bottom of the pot. Collect around 500 ml at a time, and check the EC and pH of that water. 

When the run off’s EC and pH are at the same level as the EC and pH of the nutrient solution going in ( 0.6 EC and 5.8 pH), your coco is balanced. Now you can plant your seedling or clone into it. 

Planting a Cannabis Plant into Coco

The coco is well balanced and sitting at a perfect pH and EC. It is clean and well saturated. Now you have to plant the seedling or clone into it. 

Cannabis Seedlings in Coco

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To plant a seed into coco, just make a small hole at the centre of the pot, around 1cm deep. Do not plant it too deep. You want the shoot to be able to get above the surface easily, with little effort. The deeper it is, the harder it has to work to get above the “ground”. 

Place the seed into the hole carefully, and cover it lightly. Add a few drops of your nutrient solution to gently wet the area around the seed. Then cover it with a plastic cup or humidity dome. 

You will see a shoot within a few days. 

Planting a Cannabis Clone into Coco

To plant a cannabis clone into coco, you first need to bury the pot. So make a hole in the middle of your coco that is big enough to fit the pot of the clone into it.

Place the pot into this hole, and fill around it until the top of the pot if level with the top of the coco. 

Next, carefully remove the pot from the hole, try not to disturb the sides as you pull the pot out of the coco.

Remove the clone from the pot and place it cleanly into this hole. Then level out the top of the medium. Now water the coco well, with your nutrient solution and drain away any runoff.

That is it, you’re done and you’re ready to start your cannabis grow in coco! It is going to be a great grow. Don’t forget to start your grow diary in the Coco Grow Diary Section of the forum too!  

Feeding Cannabis Plants in Coco

Now, this is coco and not soil. Things work a little different here than what you might have read or be used to with other types of grow medium. 

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First off, coco needs to be kept damp at all times, do not let it dry out! As the water is either drunk by the plant or evaporated, salts from the feed are left behind. This will raise the EC in the coco, and it can give your plant “nuit burn”. Keep your Coco wet! You can not over water it, it does not need to dry out. 

Secondly, you need to get a small amount of run off with every feed! This is to wash out old salts and make sure they do not build up in the coco. Get at least 10% run off from every feed. If you feed 1L, you need 100ml at least of runoff. 

How Much to Feed a Cannabis Plant In Coco 

Each strain of cannabis will need a different amount of nutrients. There is no guide that can tell you exactly what your plants need. But your plants can tell you!

In our example, the EC and pH of our feed was 0.6 EC, and 5.8 pH. By reading the runoff from every feed, we can tell if the plant is getting too much food, or not enough. 

Check the run off with an EC meter after each feed. If the EC of the runoff is rising, you are feeding your plant too much and you need to reduce it. For example reduce your feed from 0.6 EC, to 0.4.

On the other hand, if the EC of the runoff is falling, you need to feed your plant more and raise the EC. So 0.6 EC to 0.8. 

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EC and PH Fluctuation in Hydro
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Keep doing this with every feed until you find balance. The EC of the runoff should be within 0.2 EC, and 0.2 pH of the nutrient solution going in. When you have this, hold this level. 

What Nutrients to Use for Starting a Cannabis Grow in Coco

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You should be using a brand of nutrients that is either made specifically for coco, or has an A and B part. These will have a good amount of calcium and magnesium in them. For some idea of what brand we recommended, check out our guide on The Best Nutrients to Use for Growing Cannabis in Coco

Don’t use too much nutrients in the start! Less is more. Just use ¼ of the recommended dose of A & B, and a small amount of root enhancer. But keep the EC low. Do not use anything else! A & B with a bit of root stim is plenty for starting a cannabis grow in coco. You can add more when the plant needs it. 

Monitor the run off and adjust the EC as you need to, but only increase the level on A n B. Don’t add any other supplements. 


To Summarize

Starting a cannabis grow in coco is easy! Simply fill the pots, and water they coco with a little nutrients and you’re ready to go. It is a great medium for new and experienced growers. 

Nutrient deficiencies and excess can be detected and treated quickly. It is very hard to water your plants in coco, and it is recyclable. For any cannabis grower, coco is an excellent growing medium.

The key points to take away from this are:

Keep the coco damp at all times, do not let it dry out. This could mean watering every day. Then when you feed your plants in coco, make sure you get 10% run off. If you can follow those instructions, you will have a nice easy grow. 

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