Using Coco as a Substrate

Contributed by: Irishgi Submitted: September 15th, 2004 Images archived 2004

Coco produces excellent results for the soilless grower; it is comparable in result to hydroponics systems.

It is a great alternative to the soil grower willing to experiment with a ?soilless? medium, yet get comparable results to a hydro grow.

Coco can be used in a hydroponics system, or just put into pots and watered by hand as with any other soil grow. Countless grows for decades have been produced in plain soil, mixed with organics, compost, and perlite among untold other ingredients thrown in.

While soil does have its advantages, it also has more drawbacks: inconsistancy, unwanted (unknown) ingredients, increased chances of over-fertilizing and over-watering. Nearly all of the potting soil used has been sourced from nature contain larva and insect eggs.

*Pics shown which I grew in Coco are only 30 days into flowering, 60 days old from seed, with an intentional N def. They are not as yellow as shown. I have provided them to show the crystal/pistil covering bud/leaves more common to hydro in this stage of flowering, yet grown in coco-filled pots

The Definition of Coco
Many at first are misled by the use of the term Coco. It has nothing to do with the Cocoa plant at all. In reality, they are the brown fibers that make up the husk of a coconut, which have been washed and buffered. Pure Coco can be used as a substrate, or Coco can also be mixed in with soil.

It can be bought loose in bags; it is also pressed into planks (and bricks). Coconuts are found near beaches, oceans, places that have very salty air. To rid the coco of these salts, the coco is first washed, and then pressure steamed to get rid of salts, and bacteria, germs or anything else that might have been in it. Coco is buffered using water, enriched with Magnesium and lime. The quality of this treatment is dependant to the quality of the Coco. Coconuts cannot be bought from a store, pealed, and mixed into your soil.

(Edit: low quality coco may need to be washed to remove natural salts.)

Coco and PH
The buffering process also means easy adjustment of pH in the Coco, which is imperative when it comes to the optimum uptake of nutrients throughout the plant?s life.

Soil PH can be hard to change, since it takes time to correct, flow check and restore. It takes longer to correct the problem in soil, than it took to cause it.

The PH of fresh Coco is marked on the bag from 5.0 - 7.0, however all of the coco I’ve tested was always between 6.0 - 6.5. Changing the PH of Coco takes a few waterings of pH-adjusted water, perhaps only one. The medium is very reactive to the PH of the water given to it; this gives coco growers rapid control over pH.

What is important is that you use 6.0 - 7.0 pH water, 6.5 being optimal if in pots.

Oxygen and Coco
Soil has a tendency to become finer after time. The clumps of soil quickly disintegrate, leaving very fine pieces of matter which hold moisture, creating saturated spots, making the soil less and less aerated for roots over the plant?s life. The soil at the bottom of the pots can become a very hostile environment for the roots to grow, making roots suffocate in mud. Coco users rarely find this a problem. Coco almost never disintegrates, leaving the medium well aerated, supplying the roots constantly with enough oxygen, and all saturated spots quickly even out.

Reusing Coco
Another advantage of Coco is the fact it can be re-used. Because Coco is treated so well, you can get up to three grows from the same batch of coco. Coco is inert and does not absorb nutrients within its own fibers, so plants uptake only supplied nutrient-rich water; excess nutrients and salts are washed through with the overflow.

I paid 8 Euros for a 50 Liter bag of coco. 24 Euros in Coco, and I can fill a total of 9 seventeen Liter pots (4.5 gallon) 3 times over. Those 27 plants could go through flowering, and only averaged to .88 euro per pot in coco.

Before reusing coco, you must sift through the Coco looking for any loose root fragments, missed decaying leaves, ect. and remove them.

Advantages and drawbacks
Coco overall has many distinct advantages over soil. I have yet to grow a plant in Coco that hasn?t reached 2-2.5 feet in just 1 month from seed, without any stretching until later in life (without Topping or Fimming). The evenness of watering and the quick and direct changes of pH compares to hydro. The cost isn?t that steep because it can be reused up to 3 times, making the average cost (for myself) .24 cents US currency per US gallon. Well, after using coco, I?ll never use normal potting soil ever again

The only drawback to Coco I have found is that a massive root ball forms very quick while in veg., all my plants were detrimentally root bound in 7 Liter (1.85) gallons of coco after only 3 weeks of growth from seed. If you are ready for the growth, being in pots, and hesitant at all to go hydro with supplies and adjustments, it’s just a small hurdle for all the benefits.

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I would be interested in seeing what the coco growers think about its counterpart, soil. Thanks gang.

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I have pinned this topic for 7 days.

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I prefer chipped coco…it is great for reuse… got to watch your magnesium(epsom salt)… solves one of the biggest mistakes by newer growers over watering… you can’t over water it… got lots more but I’ll leave some room for my coco loving friends… BTW I use coco in a flood and drain system… preforms flawlessly.

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I’ve been following your chipped coco grows.

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I would be using it like soil is used in fabric pots with perlite or without perlite dunno yet…!

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if you use chipped coco you don’t need perlite…

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I can only get the Canna Brand coco coir here in CR… Chipped coco would be DANDY!

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there’s 5 or 6 of us here now that use it… all will tell you they’ll never use anything else… once you learn it’s ways there’s no going back… 21 days into flower… flawless.

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@Grower13 if you don’t mind I would like to ask some question that will help others. How many gallons of coco will you get out of a bale of coco.

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I’m good… but I got some buddies here who know it just like I do… so hopefully they’ll share as well.

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chipped coco has less expansion than coco coir… I’m able to fill 8 2 gallons pots with one bale.

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Thanks I believe if we can get the new growers to try coco they will be getting better results quicker. We just need to make the information easy for them to understand.

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This applies to me directly… My first coco grow was a disaster…

This will do?

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My medium consist of chipped coco out of the bale period… that’s all…

Beware of the fresh new coco… bit of a pain until til self adjust… after first 2 weeks with it will get good… a breakin period for new coco.

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took some pictures of my coco…
first one is a picture of coco coir with my used chipped coco… the coir doesn’t drain well and can cause over watering for less experienced growers… stays wet to long for me to use… Marijuana likes the space chipped coco has

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that’ll do… you need to charge it and/or rinse it… and just know fresh coco takes a week or 2 or 3 to get adjusted… your likely to have PH and other lockout issues until it gets adjusted to what you want it to do.

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found it… had forgot where I had it… good write up on using coco

hinking of Trying Hydroponics? Then Try Coco Coir!

Reusable, sustainable, easy-to-use and a by-product of another industry? Could the ecological credentials of coco coir be any better?

Okay so, unless you happen live in India or Sri Lanka, chances are that the coco coir you use to grow your hydroponic plants has been shipped many thousands of miles in order to reach you, but as a hydroponic medium, coconut fiber not only boasts some great ecological qualities but it also has outstanding water and air holding capacity. It can hold eight to nine times its own weight in water without becoming anaerobic-even when saturated it can still hold on to around 22% air-beating even rockwool (around 10% air holding capacity.) Coco coir is therefore a forgiving hydroponic medium, allowing roots access to enough oxygen even when watered a little too enthusiastically with a warm nutrient solution. This makes it the ideal choice for beginners!

Coco coir also boasts antifungal and root promoting properties. Coco coir can suppress and protect plants from dreaded root diseases such as pythium and phytophthora.

Qualities of Coco Coir

  • Coco has ideal pH in the range of 6-6.7
    
  • It holds 8 to 9 times its weight in water
    
  • It holds 22% air even when fully saturated!
    
  • It has excellent drainage and air porosity for better plant growth
    
  • The top layer always remains dry, leaving behind no chances of fungal growth
    
  • It never shrinks, cracks or produces crust
    
  • It aids in suppressing fungus gnats, to a degree
    
  • Excellent cation exchange
    
  • Its anti-fungal properties help plants to get rid of soil borne diseases (inhibits pathogens like phythium and phytophthora)
    
  • Extremely easy to re-hydrate after being dehydrated
    
  • It is a 100% renewable resource
    
  • Lightweight
    
  • Completely environmentally friendly
    

What’s in the bag?

There are three parts to a good, commercially available coco coir based growth medium: coco fiber, coco pith (coco peat), and chips. Each confers its own benefits to your plants.

Coco Pith

Think of coco pith / coco peat as the sponge-like component of the mix. It looks like loose tea leaves and holds a large amount of water but, because it is smaller, it facilitates much less capacity to hold air. It is more lignin (woody) and decomposes very slowly. Properly aged, it contains the complex that holds potassium and sodium until it is fertilized and a stronger ion, usually calcium, bumps these off, thereby locking up the calcium and freeing large amounts of harmful salts. Proper aging of this coco pith is therefore critical. It affects the crop time since a minimum amount of time is required to make this usable, at least four months, which reduces the amount of time available for use.

Coco Fiber

Fiber holds little water but increases the capacity of the growing medium to hold air; the more fiber you see in your coco mix, the more often you will need to water it. Fiber is largely cellulose and degrades fairly quickly. This degradation has an adverse affect on the stability of the medium. The length of these fibers is also critical to these functions as well.

Coco Chips

Coco chips hold the least water. Think of them as a natural form of clay pebbles. They combine the properties of the fiber and pith; they are approximately the same size as the fiber and positively influence air-holding properties while holding water. They have the highest air to water ratio of all three parts. Achieving the correct ratio of these components is critical in developing a well-drained, well structured medium for growth, just as the proper preparation of the chemical characteristics is important by buffering the blend before use. (Hydroponic-grade coco coir growing medium has been treated so that unwanted potassium and sodium has been removed. This helps to ensure that the nutrients you later add to the coco coir can actually be used by your plants.)

What Makes For Good Coco?

Coco coir is a natural product and, as such, the way it is harvested and prepared is key to achieving a quality end horticultural product. It is usually stored in giant piles for a couple of years at its country of origin. Unless stored carefully, these huge coco piles can be susceptible to colonization by unwanted pathogens (partly due to the pH of the coco being favorable to pathogens) so, in this case, the coco must be steam or chemically sterilized in order to make it suitable for horticultural use. However, chemical sterilization can have adverse effects; and steaming destroys the structure of the coco peat while converting any nitrogen present into a toxic form, nitrite nitrogen; both destroy any beneficial organisms that are usually present. So what’s the solution? A coco coir supplier needs to control the coconut from harvest to bagging, remove the opportunities for unwanted seed and pathogen contamination, and carefully control the aging process directly. Only then will they stand a chance of producing the cleanest, most alive and most productive form of coco coir. Regulations vary between countries with regard to sterilization (Australia is very strict). Shipping microbes across continents is frowned upon by customs agencies. Some brands are inoculated with specific microbes that are either allowed to cross borders or are blended after landing on the shores where they ultimately will be used.

Caring for the product through proper storage and packaging is critical, after preparation and again after packaging. Storing it too wet speeds decomposition. Drying in big mechanical driers can also have a detrimental effect on structure. In short, improper handling will drastically reduce the ability of the product to provide the correct root environment for proper root growth. Finally, consistency: a grower needs to be sure that they are growing in the same material crop after crop to ensure success. Imagine the heartache of losing a crop because the salts were not properly washed off your latest batch, or the coco peat is too decomposed - this REALLY happens!

So don’t be afraid to ask questions of your coco supplier. Look for an established supplier that sun dries the coco, one that incorporates the correct coco pith, coco fiber and coco chip fractions to get the best blend. This is specific to the grower’s irrigation system, the plants being grown, and the size of the pots used. For instance, you wouldn’t grow orchids in fine coco pith as they require lot of air! Conversely, any fast growing vegetable in warm conditions would enjoy lots of coco pith in the mix. Look for coco that is clean and washed correctly, one that is packaged and stored correctly, and one that is correctly aged.

Preparation

Let’s take a look at how this natural product should be prepared by the manufacturer. This is the biggest concern in selecting coco coir for hydroponics use. (Don’t be tempted to use the ‘ornamental variety’ you sometimes find at your local garden center. This may still contain high levels of salt.) The outer fibers of the coconut are removed by soaking them in water. This soaking process involves either the use of fresh water or, more commonly, the use of tidal water which can be very high in salt. As coco coir has an excellent cation exchange ability it tends to hold onto things like salt which, when used in a hydroponic or indoor set up, can wreak havoc on your plants. Good quality, hydroponic grade coco coir will have not have a high salt content, but you should always flush it through with a low EC nutrient solution before use until no more tannins are coming out. Tannins can easily be seen as they stain or color the water brown. Some indoor gardeners check to see if the PPM of the water coming out of the coco is the same as the water they’re putting in - but a more reliable method is the 1:1.5 extraction method which better determines the actual pH and EC of the coco itself.

How To Test The Suitability of Coco Coir for Hydroponic Applications

You need to get an idea of the electrical conductivity and pH of your coco coir.

  • Take a handful of coco coir and put it in a bowl. For the most representative sample, take a pinch from different parts of the bag.
    
  • Mix with about 6 oz of di-mineralized (reverse-osmosis) water and leave for a few hours.
    
  • Mix again and measure the pH.
    
  • Strain off the coco coir so you are left with just the water. Measure the EC and pH of the water.
    

A good score is around 1.0 EC. (The lower the better.) 1.3 is acceptable.
The pH should read between 5.3 and 6.2.

Many growers treat coco coir like potting mix-i.e. they use it in regular plant pots. Some add a shallow layer of clay pebbles or clean silica rock on the bottom of the pot to aid drainage and to help air get pulled through into the root zone. Drippers are a great way to provide irrigation but many growers simply hand water too.

Do I Need Coco-Specific Nutrients?

Many manufacturers offer a ‘coco specific’ nutrient formula. This is because coco coir tends to hold onto phosphorus, while only holding a little calcium and releasing small amounts of potassium. Manufacturers counter this by providing extra calcium in their coco formulations, but not so much that it competes for potassium uptake resulting in a potential for potassium deficiency.

Do they work? Yes they do but you can also use a regular hydroponic nutrient too as they contain enough calcium. Some growers swear by their coco-specific nutrients though, claiming a purpose-made nutrient is best. Aim for a pH of around 6.0 as this will allow maximum availability of all nutrient elements. As with all hydroponic applications, a little pH swing is a good thing (say between 5.5 and 6.5) as it opens the doors to different nutrients.
All in all, coco coir is an amazing, exciting and easy to use renewable growing medium. It’s easy to work with and is perhaps the best stepping stone for soil growers who want to take their first steps with hydroponics.

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a good way to charge/rinse your fresh coco before using it is to soak it in your recent used reservoir water.

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