Detailed Looked Into Coco Coir

in Coco Coir Styles Mon Nov 25, 2013 2:25 am
by ozzydiodude • The Weird One | 2.474 Posts | 11542 Points

Urban Garden Magazine takes a detailed look at the rise and rise of coco coir as a hydroponic growing media.

The glorious coconut has been providing us with much more than the odd Piña Colada for centuries. Traditionally, coconut coir (the outer fibrous husk) has been the backbone of “Welcome” doormats, brushes, sofa stuffing and horticulture for well over 100 years but, as far as hydroponics is concerned, coco coir started to make a name for itself during the late ’80s and early ’90s as a substitute for peat and rockwool, both non-renewable resources. In a nutshell (sorry, couldn’t resist), coconut coir is an environmental by-product of the long-established coconut industry. It’s a 100% renewable resource and the environmentally friendly alternative to bog dredged peat moss.

So what is it about coco coir that makes it such a popular replacement for peat and as a hydroponic medium in its own right? Firstly, check out its outstanding water and air holding capacity. Unbelievably, coco coir can hold eight to nine times its own weight in water! More importantly, coco coir holds a lot of air, in fact even when saturated it typically still holds around 22% air. In this respect it is superior even to rockwool, the world’s most popular hydroponics medium. Rockwool is a great medium but some beginners can easily run into trouble as it typically only holds around 10% air, leaving plant roots in danger of becoming oxygen deprived, particularly when the nutrient solution temperature is over 68-72°F (20-22°C). (The warmer a nutrient solution is, the less dissolved oxygen it can hold.) With coco coir, however, this type of overwatering (or, to put it more precisely, oxygen deficiency in the root zone) is avoided by the enormous amount of air that good quality coco coir can hold.

The amazing properties of coco coir don’t end with excellent water and porosity. Oh no! The best aspects of coco coir are far more varied! Did you know that coco coir possesses antifungal and root promoting properties? As coconuts spend long periods of time floating in the sea before they beach themselves and sprout a lovely new coconut tree, their physical dynamics have to be incredibly tough and unique to survive such a harsh, salty environment and still be able to sprout and grow when the time arises. These properties are available for you, the indoor gardening aficionado, to freely exploit in your quest for your perfect indoor garden. Recent studies have shown that coco coir has a great ability to suppress and protect plants from phythium and phytophthora, two very unpleasant root diseases that can quickly ruin your crop and put a real dampener on your day, week or month! This is very helpful if you are using organic-based nutrients, as these can contain high levels of urea that can build up and burn your plants.

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
Completely environmentally friendly
So what makes good quality coir?

There are three parts to a good coco medium: coco fiber, coco pith (coco peat), and chips. Each part brings its own attributes to the table.

Coco Pith

Coco pith / coco peat holds a large amount of water but is smaller and 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 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 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 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. Chips hold less water than pith or fibers. 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.)

Storage and Sterilization

Coco 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.

Finally, 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.


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. 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.

The 1:1.5 Extraction Method

A reliable method for measuring the nutrient levels in coco coir is using the 1: 1.5 extraction method. EC and pH of the root environment can be determined by using this method. The pH and EC of the drain water generally deviates from the actual root situation, as coco coir is able to retain and release elements.

1) Take a sample of coco. This can be done with a soil core sampler or a trowel. To get a representative sample the coco must be collected from as many places as possible.
2) Collect the sample in a bowl and determine whether it contains the right amount of moisture. The coco has the right amount of moisture if moisture disappears between your fingers when you squeeze it. Add de-mineralized water if necessary and mix the coco.
3) Take a ½ pint (250 ml) measuring jug and fill it with just over 4 fluid ounces (150 ml) of de-mineralized water. Add coco to the ½ pint (250 ml) mark.
3). Fully mix and allow the slurry to settle for at least two hours.
4) Mix again and measure the pH.
5) Filter this material out and measure the EC of the water remaining.

The target values for EC are between 1.1 and 1.3 (of course, lower is acceptable too!).
Target values for pH are between 5.3 and 6.2.

Reproduced with permission. Copyright CANNA.

I think the best way to get the maximum benefit from coir is in pots, as a direct replacement for rockwool or peat based mediums. Since coco coir holds so much air and water, it is a good idea to capitalize on this by placing a shallow layer of clay pebbles, such as Hydroton, or clean silica rock on the bottom. This provides excellent drainage and, more importantly, causes a huge amount of air to be pulled though when you water for feed. This assists in allowing the maximum amount of air possible into the root system and assists in pushing out the old water or feed solution.

The best way to irrigate coco coir in pots is via drippers. This is the best way to ensure that the growth media remains consistently moist (but not overly wet).

Coco-specific Nutrients

There are a number of manufacturers out there who offer a ‘coco specific’ nutrient formula. These specific formulations are based on the tendency of coco coir to hold onto phosphorus, while only holding a little calcium, while giving off small amounts of potassium. The best nutrient formulations for coco coir will therefore have some extra calcium, but not too much as it will compete for potassium uptake resulting in a potential for potassium deficiency. So are they any better? Well, generally speaking any good, complete hydroponic nutrient is more than suitable for coco coir as these invariably contain all the calcium needed to provide for excellent growth in coco coir. However, for best results, a purpose-made nutrient is best. When feeding nutrients to plants grown in coco coir, aim for a pH of around 6.0 as this will allow maximum availability of all nutrient elements. Remember, a slightly fluctuating pH is a good thing (say between 5.5 and 6.5) as it opens the doors to different nutrients. As for feeding times and frequency, that is really going to depend on what type of system you are running; but for those replacing their peat mix or rockwool with coir there is essentially nothing you need do differently, as far as feeding frequency, flushing, et cetera goes.

So there we have it. Coco coir is an amazing and renewable medium that is ‘top class’ for both performance and benefits. So go on and try this amazing medium, you’ll be glad you did.

I came across this a bit ago n I figure it may help out anyone thinking coco.

HushPuppy posted

Just to add my 2cents to this information: I have been using coco coir for several years with very good success. I found that the coco nutes were not as good as the 3part nutrients like GH flora and AN Jungle Juice. The one key that I did see repeatedly is the need for the addition of "cal/mag" supplement. I found that for my hydro system where I set seedlings and clones in coco buckets that were then set into my hydro system, the cal/mag was necessary from start to finish, with a little heavier use during the latter part of veg and earlier part of flower, then backing off to nothing during the latter half of flower toward the harvest.

I absolutely love the moisture retention and water drainage abilities of the coco coir. It works great in hydro if a fabric bag of some sort is used to hold in the finer bits while allowing water and roots to push through. I also noticed that the coco holds nutrients in the substrate and allows the plant to take it as needed without burning, as long as the pH is within range. I found for mine and a few others using coco that allowing the pH to swing back and forth across the "allowable spectrum"(as opposed to trying to maintain a set 5.8) seems to work quite well for creating happy, healthy plants. I allow mine to drift from 6.3 to as low as 5.3 before resetting with pH adjuster. :)

Dr. Madbud

Brotha Posted

In my soil mix I run Coco fiber to retain moisture. I mix 1/3 each, Pro Mix, with Mycorise, Coco fiber(block), and Ocean Forest. I mix about 20-30 gal of soil mix at a time. I chunk off my Coco into my mixing container. Put enough water into it to let the Coco saturate and break up. Once the Coco is soaked, then mix with other stuff, ready to use. I find I can put my rooted cuttings in for veg, and not have to feed them much for the first month under T5's. I use a 8 light 4x4 and it keeps my stretch down. Next month of veg, I faatten em up for the flip!
But only feeding them a single feeding for veg. After the flip, once a week feeding, water every other day for 1.5 minutes with drip system. Just enough to flood the pots. Between exhaust fans running, heat of the lamp, and the plants drinking up what it needs, I'm dry by the second morning. My watering is done auto, feeding by hand.

Let's help each other, by spreading our knowledge of the plants we love
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RE: Detailed Looked Into Coco Coir

in Coco Coir Styles Wed Dec 04, 2013 9:06 pm
by orangesunshine | 803 Posts | 3182 Points

recently working with coco at a friends garden---this is my 1st experience with it---i have decided that it may be time to mix my soil with coco---i am not yet willing to take the leap into the world of hydro/coco and held hostage to a nute program---not quite sure what i hope to accomplish or what to expect---but---i'm thinking the upside is more aeration---5 gal buckets might be bit lighter to move around lol---soil holds the nutes---less watering as the coco will retain more water---i already supplement my water with molasses to feed the myco colony---is it too much to ask to get the best of both worlds or should i stick with straight soil---if i went straight coco would the coco hold the nutrients for the uptake like soil---anybody?

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RE: Detailed Looked Into Coco Coir

in Coco Coir Styles Thu Dec 05, 2013 1:01 am
by 4u2sm0ke • Marijuana is good | 2.333 Posts | 10572 Points

I ran coco with GH3 with great results...just have to mess with the PH and crap....

take care and be safe
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RE: Detailed Looked Into Coco Coir

in Coco Coir Styles Sun Dec 22, 2013 8:22 am
by Bigjb | 5 Posts | 39 Points

I ran one of an 8 pot waterfarm system with one pot coco coir and the other 7 hydroton. The plant in the coco coir did way better than its neighbors in hydroton. I went to all coco this time. The waterfarm uses air to pump the solution up to the drip ring, so there is no water pump for the small bits of coco to get into. About a month in, on my weekly drain and replacement of solution, I suck out any debris in the bottom of the pots and reservoir with a shop vac and that kept the system pretty clean of coco debris. I am having some ph issues this time around that I did not have before.

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RE: Detailed Looked Into Coco Coir

in Coco Coir Styles Sun Dec 22, 2013 9:24 am
by Hushpuppy | 77 Posts | 323 Points

Coco can be tricky sometimes to work with. I have found that it works quite well in a more hydro system than in a "soilless" system. Yours is a bit of a hybrid of those 2 systems. The first thing to know about coco is that it has a funny cation/anion exchange rate that causes it to soak up magnesium and lower the pH within the solution. The second thing that is important to know is that it needs to be used with a significant source of cal/mag solution to offset the funny "exchange thing" that goes on, and it needs to be used from the very beginning of the plants going into the coco, up to the last 2 weeks of flower.
The third thing is to get a good quality pH meter and make sure you monitor the solution pH every 3 days if using recirculation feeding/watering.

I saw the pics over at MarP and it appears to have gotten pretty bad. It looks like a multi-element "lock-out" which can be cause by several things. I'm not sure what nute brand you are using but I have found my best results when using 3part nute solutions. I have also found that with some solutions, the pH will drift up over time and with others it will drift down over time. Drifting pH is actually good in a hydro setting(in my opinion and experience). What you have to do is start with the pH of the solution at 5.8 and then see which direction it goes, and then set it accordingly. With mine, I use AN's Jungle Juice and it always drifts down so I have to start it at ~6.2 and let it drift down to ~5.2( if you don't know this sign ~ means "about") then adjust it back up. This drift allows the pH to cross the sweet spots of all the different nute elements that the plant takes in.

I suggest for you that you flush the medium real good with straight water to get everything out and then start over with a better balance (add cal/mag at 2ml per gallon of water), Then if your nute brand is buffered, you will need to mix it up (I would mix it to about 600-800ppm) and let it sit for at least 4-6hrs with aeration going to allow the buffering to take affect. Then check the pH and make a small adjustment and allow it to set for another 4-6hrs before checking again. (this is one reason why I prefer the unbuffered nutes as I can mix it up and add my pH adjuster if needed, give it 20 minutes before checking pH, make final adjustment and pour into my system.) Once you get the solution set at 5.7-5.9 then add to your system and let it go for 48hrs before checking pH. You don't want to let it drift above 6.3 or below 5.2, however if it does go past those marks, don't panic, just adjust back to the opposite end of the acceptable pH range.

Once you get the pH swing down so that you keep the solution within the proper range (and use cal/mag along with nute solution), you will see the plants come back healthy and strong. Healthy grow mojo :-)

Doctor Madbud
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RE: Detailed Looked Into Coco Coir

in Coco Coir Styles Sun Dec 22, 2013 9:50 am
by Bigjb | 5 Posts | 39 Points

Thanks a million. Does the water I'm just flushing with need to be ph'ed to the 5.2 - 6.2?

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RE: Detailed Looked Into Coco Coir

in Coco Coir Styles Sat Jan 11, 2014 1:29 pm
by Hushpuppy | 77 Posts | 323 Points

Sorry to not get back to you on this :-( You don't need to adjust pH for water that is used for flushing as it is just going through and pulling out chems in the medium and being washed away. You only need to be concerned about pH with water that has nutrient solution as that needs to be correct so that the plants can absorb it properly :-)

Doctor Madbud

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RE: Detailed Looked Into Coco Coir

in Coco Coir Styles Sun Jan 19, 2014 6:40 am
by Bigjb | 5 Posts | 39 Points

Thanks Hushpuppy. I'm following your technique and the ladies love it! I adjust back down to 5.5 every 3-4 days and change out res every 7-10 days and they responded greatly! I'm 20 days in the flowering cycle and I am hoping for one of my better harvests.

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RE: Detailed Looked Into Coco Coir

in Coco Coir Styles Sun Jan 19, 2014 2:45 pm
by Dr Green Fang | 142 Posts | 864 Points

I didn't read everything, but to add to this, I'm going to list what I just did.

I'm growing two plants in one 4x4 tent right now, and put them into 10 gal totes. In the bottom of the totes are two 4 inch cylindrical air stones, spaced evenly apart and mostly in the middle(ish) part of the tote. I then just about covered those (and the bottom) with about 2 inches of Hydroton in the bottom. After this, I mixed up 1/3 Sunshine Advanced Mix #4 (Peat Moss, Coco, Perlite) with 2/3 Coco+additional Perlite.

This is something HushPuppy and I have been talking about for a couple months.

I sure do love Coco! :)

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RE: Detailed Looked Into Coco Coir

in Coco Coir Styles Sat Feb 22, 2014 9:11 am
by Hushpuppy | 77 Posts | 323 Points

Anyone with questions about working with coco coir? I certainly don't know everything but coco is my preferred medium so I am happy to help anyone in need. I am still intermittent with browsing so if you have questions please PM me as I will se that quicker and respond to you sooner

Doctor Madbud
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