- Hi, this is Ethan with Bright Agrotech.
Today we'll be talking about pH.
We'll give you a brief introduction
on what it is.
We will tell you how do manage pH.
And also offer some troubleshooting tips in relation to pH.
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pH is a measure of how acidic or how basic a solution is.
Acidity means a pH below that of seven, which is neutral.
Basic means a pH above seven.
pH scale runs from one to 14.
pH by definition is a logarithmic measurement
of the hydrogen ion concentration of a solution.
What that means is you're measuring the H+,
which is a positive ion,
or OH-, which is a negative ion in solution.
One is acidic, one is basic.
Most hydroponic systems will require a pH
somewhere around 6.0 to 7.5.
I have found that 6.0 to 6.5 is a really nice range
for most herbs and greens.
So why is that pH range, maintaining a nice stable range,
somewhere between 6.0 to 7.5 necessary?
That is due to the fact that availability of the nutrients
in your hydroponic solution will vary with pH.
If you go too high or too low,
you might lock out certain nutrients.
And you'll see deficiencies within your plants
and slowed growth, not a good thing.
So if you keep it right at that happy medium,
your plants will be happy and get most of what they need.
A little bit of pH flux can sometimes be a good thing
because it gives them a small variance in what is available.
So various crops will have varying nutrient
and pH requirements.
So some crops will be very high pH requirement,
most however tend to be on the acidic side of things.
If you're looking to find good information on that
there is tons of peer reviewed research
on which crops like which pH online.
You can also refer to Upstart University
for this information.
So how do you manage pH?
First to manage pH you're going to need
some way to monitor it.
So what we have here is a hand-held pH meter.
This also will read nutrient concentration as well.
But you do need to monitor your pH,
monitor it daily, it will change and fluctuate.
We also have other varying methods to monitor pH,
including auto-dosing systems
which will hookup to your main reservoir
and dose for you from a reservoir or tank
of pH Down.
We also have old-school litmus style tests,
which is a strip of paper that will change color
depending on what the solution pH is
when it is exposed to that solution.
So if you have an auto-doser
or a hand-held nutrient meter,
you will need to calibrate it
for pH as well as EC if it has that functionality,
but that's a story for a different video.
To calibrate your meters
you will need a calibration standard.
This is something that is very exactingly produced
and it never changes, it is always pH of 7.0.
Sometimes these will have expiration dates on it,
so be mindful of that.
Typically you will need a 7.0 and a 4.0
to calibrate your meter.
Most calibrations are pretty quick and simple,
your meter will have instructions on it.
It is also recommended to get Probe Cleaning Solution,
if you have a dirty probe, it will not read correctly.
This stuff goes a very long way.
So, as far as what really works for these testing methods,
the best ones are a reputable hand-held meter
as well as an auto-dosing system.
However the price of these may put them out of range
for most home growers and it may be necessary to use
an old-school style strip kit.
Strip kits are not the most accurate,
there's a little bit of personal perception involved
in what color you actually see on the strip.
So it can vary a little bit in what you're reading
but it's better than doing nothing.
You do want to buy a meter from a reputable brand.
Brands like Autogrow, brands like Hanna Instruments,
Oakton, Blue Lab, they all make reputable products,
don't just go and buy the cheapest thing on Amazon
because it more than likely will not work very well
or for very long.
So adjusting pH.
Once you've got a way to monitor your pH,
you can actually take steps to adjust your pH.
Now depending on what you do to adjust your pH,
will depend on the pH of your starting solution,
I.e. what is your tap water at
when it's coming out of the tap?
Here in Laramie our pH, we are fairly lucky,
it's close to neutral.
So we wind up using pH Down frequently.
It will vary from season to season,
so it's good to check your tap water regularly.
Right now ours is currently at about 6.8,
so we use pH Down to reach a target pH
of about 6.0 to 6.2.
If your water is lower than neutral and acidic
coming out of the tap you will want to use pH Up.
There are other various methods to raise and lower pH
other than store-bought pH Up and Down,
however I do recommend using these
because they will not alter other aspects
of your nutrient solution
and they are a constant solution
so they will always be the same
every time you purchase it.
So for example, you may think
that if you have an acidic tap water source
you can take just about any base to raise that.
You might want to take sodium bicarbonate,
something like that, even lye, something that's high pH,
that would be a bad, bad idea.
A lot of times this can be harmful for the plants,
it can be harmful for the microbial life
in your nutrient solution
and is just generally a bad idea
because a lot of times these methods
can change the electrical conductivity
of your solution as well.
So once again, I recommend using a constant,
store-bought solution, this will always be the same stuff
no matter where you buy it
and you can always add the same amount
as long as you're sticking to the same brands,
usually even between brands, they're very, very similar.
One major reason to do this
is you're not going to save a whole bunch of money
by using a household product to lower or raise your pH
unless your pH of your water is very extreme
it will take very, very small amounts of this
to change your pH.
Even in our medium-size test farm,
we go through very small amounts.
A gallon of this will last for months here
and we are dosing a 300 gallon reservoir with this.
So when it comes down to actually adjusting pH
I cannot recommend auto-dosing systems enough.
pH can be difficult to adjust
for someone who's not experienced in it.
By and large because this is very concentrated solution,
so a very small amount can go a very long way.
As I said we use a 300 gallon reservoir in our farm
to dose a brand-new solution
and take it from a roughly neutral pH
of tap water that we have here,
it takes only about a cup or a cup-and-a-half
to bring it down.
So as I said, a gallon will last quite a long time.
If you're at a very, very small reservoir,
you know under 20 gallons,
you might want to start with a teaspoon,
let it circulate through your system,
check it again,
always be checking your pH.
If you're doing it manually and trying to adjust it manually
check, check, check, because it will change.
It will change frequently.
If you are using pH Down in an auto-dosing solution,
that means you are drawing your pH Down
from a reservoir with your auto-doser.
I recommend starting on the low side
when filling up that pH Down reservoir
because we have actually experienced
some situations where if you get that solution to acidic
and you put in too much of this,
you will get acidophilic bacteria
growing inside your pH Down reservoir
which is not a good thing.
However, your mileage may vary
and you may not have to worry about that
if you're adding pH Up.
So since pH Down can be hard to adjust manually,
I actually do not try and mess with it.
For our small reservoirs, typically speaking,
reservoirs that are under 50 gallons or less,
the reason for that is
our tap water is usually right around neutral,
right now this time of year,
we're reading about 6.8.
So we're already pretty close to that range
that's good for plants.
Now if you add nutrient solution,
usually nutrient solution is a little bit acidic,
so that will slightly lower your pH as well.
So we get a little closer to that mid-six range
that's really nice.
Plants also do a thing called selective ion uptake.
As we mentioned earlier in the definition for pH
it's a measure of the hydrogen ion
concentration of solution.
So with plants taking up certain ions,
leaving certain other ones behind
our pH tends to stabilize slightly down,
a little bit more from the action of those plants
so we wind up right about in the middle
of that pH 6.5 range or so, right about there.
This will not always work for all solutions,
it really depends on your tap water.
Is your tap water, you know pH of eight?
It's not gonna work.
Another common problem when troubleshooting for pH issues
is you might have high carbonate content in your water.
It's very common in our water.
What this does is it buffers the pH
and it makes it really hard to adjust.
So it's buffering that pH at a high pH range
and even adding this a lot of times
won't change it very much,
because there is such high carbonate content
in that solution that it's just buffered and stuck
right at that high range.
If you are over 200 parts-per-million in carbonates
and the only way to do that is to have your water tested
to find out for sure what your carbonate content is,
if you are over 200 parts-per-million
it is highly recommended that you get an RO filter system
to filter your reservoir water before putting it in.
So, what are some common mistakes that you see
with using pH Up or pH Down to adjust your pH?
As we had said earlier, you do not want
to use household products,
something that's going to be varying.
You want something that is constant,
something that you can rely on time and time again.
Don't mess around with other stuff and experiment,
you might kill all your plants.
Other common mistakes that you will see
is adding way, way too much of it,
too fast to your reservoir,
as I have said in earlier sections,
add a small amount, let it circulate through the reservoir
and recheck, come back, you know sometimes it depends
on the size of your system,
but you might want to come back up to half-an-hour later
to give it time to fully disperse into solution
'cause you will see constant variation
and you don't want to see huge, huge pH swings
when you're adding, it's better to adjust it slowly
so that the plants do not get any shock from that.
So to avoid making that mistake
of overdosing your system with your pH adjustment solution
you want to use a measurement tool always.
And always start with a small amount
once you have a feel for how it changes your water
and how it changes in relation
with your nutrient solution
because nutrient solutions
are typically a little bit acidic,
they will slightly lower your pH as well.
Once you have a feel for that
you can kind of get into the habit
of knowing okay, my 20 gallon reservoir takes,
you know a tablespoon to drop the pH this much.
In relation to what your pH is reading,
if it's too high or too low you're plants
may not have the available nutrients that they need.
It may be in solution but they can't use it.
A pH range of six to 7.5 is recommended,
usually mid sixes, are pretty good.
In conclusion, pH is extremely important to plant growth
and should be a top priority.
So we hope you liked our video.
We hope you learned a lot.
If you have any questions,
if you have any comments,
if we left anything out of this video
that you would like to know
please let us know in the comments below.
Again, I am Ethan Walter, here with Bright Agrotech,
until next time.
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Other commons mistakes, this does look tasty,
it is a nice orange drink color.
Do not drink it, it probably won't be very good for you.