Bigger Buds

These are the cation exchange capacities of different
soil structures at pH 7.0. You can clearly see how
important the addition of humus is to your soil and
growing mediums’ ability to hold a stable pH. You can
easily build more humus structure in your soil and
growing mediums by adding humic and fulvic acids
to them. As an aside, if you’re an outdoor grower
you can now see the importance of growing in soils
with high humus values because it will definitely
make a difference in getting you bigger yields.
Well, each one of them has a certain ability to stabilize
or buffer pH, which is another way of saying they
have varied abilities to keep the pH from changing on
you. This ability is called cation exchange capacity
or CEC.
In other words, CEC refers to the ability of the
medium to absorb and release cations. Remember
the cation stuff I mentioned at the beginning of this
report? We’ll be looking at this a little bit closer now.
Dependent vs. Independent
Mediums that are pH dependent have little to no
CEC and cannot resist a change in pH and this
results in the pH going high or low very rapidly.
So, then, mediums that are pH independent have
a high CEC, are more buffered and can resist a
change in pH for long periods of time. And that’s
good! That’s what you want.
As an example, your everyday, garden, soil-based
medium contains some humus and clay and is pH
independent with a high CEC because of the humus
and clay. They are great to grow plants in because
they are not affected by rapid pH swings.
But Indoor Growers Have To
Follow Different Rules
Now, hydroponics is different. Many of its mediums
have a low CEC and need to have the pH continually
balanced and monitored. More on this later. Of
course, there are some that have a higher CEC and
are better buffered than others. For example, coco
coir and sphagnum moss have higher CEC capacities.
This means they are capable of maintaining
a more stable pH level. These are said to be pH
independent. Sphagnum actually has eight to ten
times the CEC as soil pound for pound, but there
are other drawbacks.
But not to worry, these could be easily remedied,
though no manufacturer has done this yet. You see,
sphagnum doesn’t have the bulk density that soil
has. After all, it is a moss and is light in weight. But
you can add something called calcined clay to solve
that problem.
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