Coco coir is a popular root-zone media for cannabis cultivation that, if not correctly applied, can cause problems for your crop, including harming growth rate, potency, yield — and your bank balance. But if you master the following coco coir facts and hints, you’ll be well on your way to growing high yielding, potent plants to knock their socks off.
1.The Way In Which Coco Coir Is Manufactured Will Have An Effect On Your Grow Op
As with soil, soilless mix and rockwool, there are many coco coir manufacturers, but only a few of them make trustworthy, quality grow-op products to enhance your grow.
Coco coir comes from coconut husks. The quality of the coco coir is dependent on where and how the husks are sourced, and the age of the husks. Some coconut husks are loaded with sodium and toxic contaminants, thanks to ocean water or storage ponds, while other husks are too green and immature to be processed into quality horticultural material.
The processing of coconut husks involves washing them with fresh water at the right temperatures over a period of time, before carefully treating and drying the material. This preparation should activate the breakdown of the husks into coco peat fibers that will afford your cannabis water-holding capabilities, aeration, internal consistency and durability.
Processing of husks should be carried out using professional facilities, methods and materials. If inferior materials and methods are used, then the resultant inferior coco coir tends to become waterlogged or break down quickly, leading to drowning marijuana roots.
If the husks and fibers are not washed and treated correctly, the finished product can also have unsolvable nutrient problems, including wrong or insufficient amounts of nitrogen, calcium, iron, magnesium, potassium, sodium and chlorine that may harm or even kill your cannabis crop.
And coco coir must also be graded, packaged, shipped and stored correctly so that it works well for your grow op.
For that reason, you’re probably wondering what is the best coco coir brand. I’ve tested all major brands and many off-label ones, and have experienced intermittent or pervasive problems with each of them, especially with Canna and Botanicare.
I’ve also experienced significant variations in coco coir quality from batch to batch with the same manufacturer. A good place to start is by ask your hydroponics store what brands of coco coir the staff is most likely to recommend.
2. Always Wash & Test Coco Coir Before Using It In Your Grow Op
No matter what the manufacturer tells you about the quality, pre-washing, processing and usefulness of a coco coir product, you must always start by washing and testing it yourself before you put it to work.
Begin by buying the smallest amounts possible of the top two coco coir brands recommended by your hydroponics store. Next, test the products using the following method:
- Put the coco coir in a two-gallon bucket that has holes in the bottom, and place that bucket inside a five-gallon bucket.
- Using reverse osmosis water, pour 2.5 gallons of water at pH 5.7–5.9 through the coco coir, collecting the runoff water in the five-gallon bucket.
- Test the parts per million and pH of the runoff water.
- If the parts per million reading is higher than 450 ppm, and/or the pH is wildly out of range, repeat the experiment to see if you can get runoff water that’s less than 450 ppm and within pH range.
- If you rinse your coco coir more than three times and it’s still showing 450 or more ppm, and/or the pH is out of range, do not use that coco coir.
Rinsing and monitoring takes time and you may go through several brands of coco coir before you find a quality product that works for your grow. When I rinse coco coir and the runoff pH is within range, and the runoff parts per million is below 300, that’s the coco coir I trust to use.
Once you find a test amount of coco coir that has low runoff parts per million and acceptable runoff pH, buy that product in bulk. However, because batch quality varies, if there is no more of the same batch available at your supplier, then you’ll have to start testing a new batch.
3. Buying The Best Form Of Coco Coir For Your Cannabis
Beyond finding well-manufactured coco coir that performs well in runoff pH and ppm tests, you want coco coir that has the right consistency and configuration.
Coco coir comes in a variety of compositions, including condensed bricks, loose fiber, coco peat blocks, and coco coir fibers mixed with perlite. The best way to grade the usefulness of coco coir in your grow op is to wash and measure it yourself before physically handling and examining the product.
You’re looking for dark, clean, golden-brown fibers with the consistency of moderately dry soil. The coco shouldn’t have clumps or be comprised of fine powder.
Many growers, particularly those who grow using the sea of green method, use coco coir in raised grow tables, while others use it in individual pots. Coco coir that comes with perlite is more expensive and the costs can quickly add up, especially if utilizing a grow room that tends toward high humidity. If so, I might cut the coco with 10 percent coarse perlite.
Bricked coco is usually less expensive, but harder to work with, so I prefer loose-fiber coco coir.
And again, buy a small amount first, so you can thoroughly inspect and test the coco before you invest in the larger amount for your season.
4. How To Water Coco Coir
Coco coir retains water well — too well, if you’re a cannabis grower who tends to overwater. On top of that, the physical appearance of coco coir isn’t necessarily a reliable gauge for knowing when the medium needs more water.
Coco coir should be watered when it’s 50–70 percent dry. But how can you determine the dryness of your coco coir?
The following technique works well, but only if you’re growing in individual pots:
- Water until about 15–20 percent of the water runs out the bottom of the pots and the coir appears to be thoroughly wet.
- Weigh the pots and record their weight. If they’re evenly watered, they’ll all weigh about the same.
- When you believe 50–70 percent of the moisture has left the coco coir root zone, weigh the pots again.
- The difference between the initial wet weight and the dryer weight is used in a percentage calculation to determine how dry the coco has become.
If you’re cultivating cannabis in a grow table or don’t want to weigh pots, invest in a tensiometer, a device for measuring root zone media moisture. A tensiometer accurately calculates soil water tension, which tells you the effort required by your cannabis roots to extract water from your root zone media. Most soil moisture meters won’t work as well for other grow mediums.
Tensiometers are relatively inexpensive and can be used in coco coir, soil and soilless mix. Take a look at these instructions from Agriculture Victoria about how best to use tensiometers.
Coco coir is particularly sensitive to salts and contaminants, because it has chemical and physical properties that interact with water and whatever’s in it in ways that no other cannabis root zone media does. For that reason, it’s best to always use reverse osmosis water.
Also, coco coir is like a sponge. Too many coco coir growers end up drowning their cannabis roots, especially with seedlings and clones that don’t yet have fully formed root systems.
5. Using The Right Nutrients For Growing Cannabis In Coco Coir
If you use regular hydroponics nutrients or organic nutrients with coco coir, you’ll almost certainly see crop problems. By that logic, I used to avoid growing in coco coir, until I realized it was the fertilizers I was using and not the coco coir that caused my grow problems.
Growers using the wrong nutrient brands with their coco coir grow op report seeing growth, yield and potency problems, especially because coco coir tends to lock out magnesium and calcium crucial for photosynthesis and bud development in bloom phase.
Advanced Nutrients pH Perfect Sensi Coco Grow and pH Perfect Connoisseur Coco Grow base nutrients contain pH-buffering features that eliminate the common problems growers experience when attempting to grow in coco coir with other nutrient brands.
These two base nutrient products eliminate coco grower problems because they contain the proper forms, ratios and amounts of calcium, magnesium, iron and potassium for cultivating in coco coir.
Before Sensi and Connoisseur pH Perfect coco coir base nutrients were on the scene, growers often struggled with nutrient-related problems that forced them to use cal-mag supplements that created more problems than they solved.
Growers also harmed their cannabis crops with repeated flushing, underwatering, overwatering, and trying different nutrient parts-per-million concentrations,.
Coco coir growers have reported faster-growing plants and bigger, more potent buds when they use pH Perfect coco coir hydroponic base nutrients that automatically balance water and root zone to the ideal 5.7 pH, so that crops easily absorb all the nutrient elements they need.
High-yielding bloom boosters in the Advanced Nutrients range of products are fully compatible with Sensi and Connoisseur coco base nutrients.
I especially recommend using Advanced Nutrients’ three beneficial microbes products Voodoo Juice, Piranha and Tarantula, because coco coir is an ideal host for beneficial microbial colonies that increase root mass, root function, root health, plant vitality and bud size.
Additionally, Bud Candy feeds carbohydrates to the beneficial microbes, while Big Bud Coco remains the only bloom booster engineered with proprietary ingredients to maximize bud development in marijuana growing in coco coir.
To summarize, Advanced Nutrients coco-specific nutrients coupled with quality coco will give you the following benefits:
- Coco coir holds water well, so you use less water, and water plants less frequently.
- Coco coir is an ideal host material for beneficial, root-enhancing microbes.
- Coco coir can sometimes be recycled for use in multiple crop cycles. Use Sensizym root cleaner to cleanse coco coir of organic root zone debris so the coco can be safely reused.
- The favorable oxygen/water ratios of coco coir provide more oxygen to roots and prevent waterlogging, which increases growth rate and bud yield.
- Coco coir is a mostly inert medium that works well with hydroponics and organic nutrients. If you want to grow organically using coco coir, use the organic supplement Iguana Juice, which is made specifically for cannabis and works well in coco.
There are many cannabis growers who won’t use anything other than coco coir. If you wish to emulate their success and enjoyment of cultivating using this medium, mastering the points outlined here will bring you closer to harvesting big, sticky, potent yields from your grow op.