pH: Everything you Need to Know

Know our pH

First, measure the pH of the water in the reservoirs when entering the indoor cannabis garden.  In addition, pH is a scientific measure of water in order to observe “acidic” and “alkaline.”  Understand that pH measure has a 1-14 range.  In addition, pH neutrality is 7, lowest acidic value is 1, and highest alkaline value is 14.  Further, pH measurements relate to concentration levels of hydrogen in the water sample.  The indoor cannabis gardener will measure pH with tester strips/ measurement kits, drops, digital pens, and or computer probes.

Watch a video teaching the importance of pH.


Why is managing pH important?

Through pH maintenance we mitigate risk to cannabis plants and nutrient deficiencies.  Nutrient deficiencies inhibit cannabis plant growth.  As well, appropriate nutrient maintenance stimulates more effective, efficient, and larger yields.  Creating standard operating procedures for daily monitoring of pH reduces risk and mitigates damage to the root zone and overall cannabis health.  For example, when we determine the pH is not our nominal value we alter pH before visible damage to the leaves or root zone.

Importantly, pH regulates nutrient absorption in the root zone of the cannabis plant.  Further, pH imbalances lead to nutrient lock out, which is often mistaken as nutrient deficiencies.  Therefore, before considering nutrient deficiencies  we need to check pH values before total dissolved solid values, part per million values (ppm), or electromagnetic current (EC).  Inexperience in cannabis growing often leads beginners to nutrient burn due to inappropriate regulation of pH.

Thus, the theme for nutrient lock out is not the lack of food, however, the cannabis plant’s inability to process the nutrients at the current pH value.  Accordingly, when a cannabis plant is unable to absorb nutrients creating nutrient lock the next challenge is salt build up.  Salt build ups occur more quickly when pH values are not nominal and the nutrients are absorbable. Consequently, salt build ups increase challenges to the roots of the cannabis reducing water and nutrients absorption capabilities.


How does pH effect nutrient regulation in cannabis roots?

Nutrient absorption depends on the chemical makeup of the nutrient, as well as, the pH value of the water.  In addition, some nutrients are only absorbable at a specific pH value.  When pH is not at the nominal value the cannabis plant often portrays signs of nutrient deficiency despite nutrients at the root zone.  Appropriate pH facilitates consistent nutrient access for cannabis.

Cannabis prefers an acidic environment at the root zone. Therefore, as we observe cannabis growing in the wild we see cannabis prefers an acidic pH.  Please read the following closely.  A pH value of more than 6.2 and cannabis will not absorb potassium. As well, a pH value above 7.0 and cannabis will not absorb phosphorus. Further, a pH value of 5.5 or below and cannabis will not absorb nitrogen.

In conclusion, once cannabis transitions into flower the locomotive has already built up so much speed.  If something is on the train tracks at full speed there can be serious injury.  Importantly, any challenges during flowering to cannabis reducing optimum performance levels effects potency and yield.  Therefore, challenges the cannabis gardener encounters need appropriate diagnosis in order to respond accurately, timely, and effectively.

Appropriate pH range for cannabis?

The appropriate pH range for cannabis varies on growth medium.  For example, an organic soil garden pH desires a nominal value of 6.3 for cannabis.  Whereas, gardening hydroponically requires a pH nominal value between 5.5 and 6.5 for cannabis.  Our digital pH meter is our first most important tool in hydroponic gardening.

Further, digital pens measure pH, as well as the proportion of nutrient salts (tds/ppm/EC) within the water.  Our pH readings inform us of our cannabis happiness.  Therefore, our ability to diagnose pH challenges is our first priority in diagnostics when evaluating unhappy cannabis.  Our pH digital meter is our diagnostic tool, informs us of root zone challenges, nutrient absorption rates, and overall happiness.


Why is the pH changing?

When we test our pH and readings are above 6.3 we may consider the cannabis is absorbing a disproportionate amount of water to nutrient ration.  Disproportions between water absorption and nutrient absorption can connect to higher air temperatures and low humidity levels.  However, the mindful cannabis gardener also considers algae, fungus, and bacteria buildup in the water reservoir or root zone.

Consequently, when algae, fungus, or bacteria are present in the cannabis environment pH values will not be nominal.  Algae buildup propagates in our nutrients with water temperatures ranging from 76-85 degrees Fahrenheit.  In addition, to light penetrating into our reservoir and light exposure to the flood table.  Whereas, algae itself does not harm our cannabis, the death and decay of algae creates Pythium.  Further, algae Pythium creates terrible odors, which ultimately effects the taste of cannabis.  More so, algae clogs our air lines, water lines, and other tubing.  Most importantly, algae may cause detrimental pH jumps overnight due to Pythium.

For soil, when our pH is acidic and ranges from 5.2- 5.3, a cause may result from nutrient solution being too high for cannabis at the current stage of growth. Here, we flush cannabis with alkaline water until the pH reaches the nominal value for both pH and parts per million.

What is the appropriate pH level?

The appropriate pH level for soil is ranges 6.0-7.0 pH.  In contrast, the appropriate pH levels for hydroponics, soilless gardens, rock wool, and coco coir is ranges 5.5-6.5 pH.

Cannabis in soil prefers an acidic root environment in the wild. Therefore, for cannabis in soil with nominal ranges of 6.0 and 7.0 pH there will be fluctuations.  Cannabis in soil appreciates a fluctuating range of 6.2 – 6.9 pH.  When cannabis is in soil we allow the pH to cover the nominal range in order to absorb as many nutrients as appropriate.

Appropriate pH levels for hydroponics, soilless gardens, rock wool, and coco coir is ranges 5.5-6.5 pH.  When growing cannabis with hydroponics we need to be additionally mindful of our pH range.  Importantly, we want to allow our cannabis pH range to fluctuate from 5.5-6.5 in order to absorb the gamut of nutrients available.  In our hydroponic cannabis gardens we primarily use liquid and powder nutrients.  The vast majority of nutrients on the market do not effect pH. Therefore, pH naturally fluctuates, and we only correct pH when our nominal 5.5-6.5 range is not present.


Important pH fluctuation, embrace micro pH changes

The cannabis gardener does not need a perfect every time reading of pH.  The indoor cannabis gardener does need to be mindful of harmful macro pH alterations to the root zone.  Thus, observing nominal pH ranges of 5.5-6.5 in hydro and making adjustments only as appropriate for the nominal range is the best risk mitigating technique.  In conclusion, the nominal pH ranges of 5.5-6.5 will reduce, prevent, and mitigate the majority of nutrient challenges in relation to pH values.

Importantly, a wise idea is to allow pH diversity in the nominal range.  We observe the nutrient absorption pH ranges in our diagrams and understand the importance of nutrient pH absorption relation. Conclusively, some nutrients better absorb at more acidic pH levels and other nutrients at more alkaline levels. Therefore, we save ourselves time, frustration, and money by allowing pH diversity.

When our cannabis roots experience inappropriate pH, the skillful, and mindful cannabis garden takes immediate action.  Further, without immediate action challenges will increase and potentially multiply themselves.  Therefore, become consistent in testing pH daily, observing the pH diversity, and documenting changes over time.

We do not need to be exact. We only respond to our cannabis garden when pH values are outside of the nominal range of 5.5-6.5 pH.

Standard operating procedures for mindful cannabis gardeners requires pH testing of the tap water, reverse osmosis water, and distilled water before every water change out.  As well, the mindful cannabis gardener engages in testing the parts per million and electrical conductivity before the water change out.  Additionally, when we do a water change out or partial water change out we add our nutrients to the water first, then check and adjust pH appropriately. Nutrients may effect pH so we adjust pH after as a risk mitigating technique to save time and money.


How do we lower pH for our cannabis garden?

We use the chemical phosphoric acid to adjust our cannabis pH.  When we go to our local hydro store this is the “pH Down” we see for purchase. Our liquid tools are pH Up and pH Down.  As well, cannabis gardeners incorporate swimming pool pH adjustors depending upon cost and availability.  The indoor cannabis gardener will measure pH with tester strips/ measurement kits, drops, digital pens, and or computer probes.

Our method of choice is the pH digital reader and computer probes.  More so, digital readers and computer probes are most scientifically accurate when calibration is appropriate.  Measurement kits are effective, however, do not deliver the same accuracy or validity of a pH digital reader.  Yet, a measurement kit is nice to have on hand when we believe a pH digital tester or probe may be inaccurate or broken.

Every cannabis garden needs an inventory of “pH Up” and “pH Down.”  Mainstream pH Up & pH Down gives us the most convenient opportunity to adjust pH in soil and hydro. General Hydroponics provides cost effective pH products.  There are many brands on the market, however, choose the most cost effective brand available. Mainstream supplier such as General Hydroponics and Mad Farmer allow us to easily measure appropriate volumes to add to our water.

Further, do not use vinegar or baking soda to adjust pH.   We do not use vinegar or baking soda to adjust pH because they are not easily measurable to adjust pH appropriately.


Steps to adjust pH cannabis levels

First we add our nutrients to our reservoir or watering container.  The cannabis gardener does this first because nutrients may alter our water pH.  Indeed, many nutrients are pH stable. The mindful cannabis gardener always engages in risk mitigation as able.

Secondly, if we do not have bubblers, we stir the water.  If the cannabis gardener has bubblers they move onto step three.  Third, the cannabis gardener takes a sample of the water.  The sample needs to be enough to fully submerge the digital meter or probe.  Importantly, your pH digital meter or computer probes need to be in an appropriate calibration.  Standard operating procedures for Captain Sunshine requires all gardeners to clean digital meters after use and computer probes every other week.  In addition, standard operation procedures from the Captain requires calibration of pH tools bi-weekly.

Fourth, the cannabis gardener adds pH Up or pH Down to their water.  Captain prefers to use syringe style measurement devices.  Preferably, devices that hold from 0-10ml.  Captain does not like to use beakers when using pH down because acid may splash when in pour rather than sucking in with a syringe.  The mindful cannabis gardener always wears food safety gloves and safety glasses when handling cannabis tools, especially acid.  The mindful cannabis gardener will add micro doses of pH Up or pH Down.  A micro dose is 1-2ml.  Therefore, continue to add more solution as appropriate to reach the pH of desire.  Dose and test, dose and test, and dose and test.

Fifth, is our dose and test phase.  Repeat the fifth as appropriate.  Hydroponic growers need to be mindful of how many liters per minute their bubblers work.  Thus, provide an appropriate amount of time for the dose to dissipate into the reservoir.

Sixth, water your soil plants.  Otherwise, your reservoir should be happy now.  Hydroponic gardeners should never dose to an epicenter or to the flood table.  Always dose the reservoir.

Seventh, soil grower will test the pH of the water runoff.


Micro dose your cannabis pH Up and pH Down

The amount of pH Up or Down we add will vary depending on our water. If we are using very soft water than we will need just a tiny amount of fluid to adjust the water’s pH since there’s not much “stuff” in the water to buffer the pH. However, if you’re using hard water than you’ll need to add more.

Foremost, mindful cannabis gardener’s micro dose pH down.  The general rule is 1 mL/gallon of water often reduces pH by 1 point. Accordingly, that’s what we call SWAG or Scientific Wild Ass Guess, however allows a beginning baseline. Otherwise, imperial measurements, equate to 0.2 tsp a gallon, 1 tsp per 5 gallons, and should reduce pH by 1 point. Captain Sunshine prefers a blunt-tip syringe with mL measurements.  This is for safety first, then science, and then user friendliness.

Captain Sunshine has numerous experiences with reverse osmosis and soft water.  Often, we need less pH down for RO water.  However, some gardens vary due to hardness of the water and require disproportionate amounts of pH adjustor.

When considering pH UP the liquid requires more in order to take an appropriate effect.  Whereas, pH down often requires less volume of solution.  The general rule of thumb for cannabis gardeners is 2-4mL pH UP a gallon to raise the pH 1 point. Whereas, imperial measurements equates to 0.4-0.8 tsp a gallon.

Accordingly, the first time we adjust our pH, we are not aware of how “hard” our tap water is.  Whether or not the pH is 7.0-8.0 with 300-400 ppm.  However, Captain Sunshine and friends live in San Diego where our water quality is poor.  In addition, Sunshine has friends with well water which is extremely delicious depending on water table quality.  More so, Captain has experiences with extremely high contents of iron in well water.   Further, distinct nutrients and supplements can effect pH. Furthermore, his is why the mindful cannabis gardener micro doses all fluids in the hydro garden.

As well, Captain standard operating procedures require tracking and monitoring of pH adjustments into an excel spreadsheet.  When tracking pH Up and pH down we document the amount of water in the reservoir or the amount of water for feeding.  Dependent upon the reservoir size or watering needs will determine overall mL values.  When monitoring pH over time we can observe healthy cannabis nutrient absorption rates which parallel healthy pH levels with healthy ppm levels.  Hopefully, the amount of pH volume in use remains at similar values.  Deviations in the amount of pH adjustor requires investigation if shifts are dramatic.  However, pH values and the amount of volume for adjustment will change depending on the nutrients cannabis is being fed and in which stage of life.

Unfortunately there is not a scientific formula for pH adjustment.  Variables in pH relate to the water source, nutrients, grow mediums, drain to waste and other cannabis garden setups.  We use the scientific method to observe through experiment and observation to determine the amount of pH Up and pH Down.


Standard operating procedures for cannabis nutrients and pH maintenance

First, the mindful cannabis gardener micro doses all nutrients, pH adjustors, and garden liquid tools.

Secondly, the mindful cannabis gardener never mixes nutrients with one another.  Therefore, always add nutrients directly to the reservoir or the watering container.  Adjustors to pH are put directly into the reservoir or the watering container.

Third, the mindful cannabis gardener always wears food safety gloves. As well, wear safety glasses to protect our eyes from intense lighting, and splashing of liquids.

Importantly, the first task in the garden when no visible light issues or other challenges, is to test the pH.  Then, after testing pH we test ppm. In addition, after testing ppm we record air temperature, humidity levels, and Co2 levels.

A critical element of successful cannabis hydro gardening is water change outs.  Captain standard operating procedures require a water change out or partial water change out every two weeks.  During summer months, extreme heat waves, or recovering cannabis requires weekly water change outs.


pH and soil

When we water our grow medium we test the water runoff, which is the water that gathers at the base.  Our goal is to have the runoff pH levels be appropriate.  Whereas, even if the pH was not appropriate when we feed, the important factor is the runoff pH.  We only adjust the cannabis pH is the runoff is not appropriate.

The mindful cannabis gardener always documents the pH level of the water in use during feeding.   We check our excel spreadsheet before entering the garden every day in order to engage in quantitative data gathering. The mindful cannabis gardener more easily observes challenges, changes, alterations, deviations, and cannabis appropriateness with daily monitoring and tracking.  Further, this allows the cannabis gardener to engage in continuous quality improvement.   Continuous quality improvement allows the cannabis to set their personal standards in order to reach their goals and dreams.

Whereas, with soil we can engage in flushing techniques to reduce pH levels.  High pH levels in our cannabis soil can be a result of over-fertilizing, a buildup of salts, root rot, pests, and other biological invaders.  Thus, we believe our pH is in need we can flush the soil to remove salt buildup and to attack any predators. Flushing is only an option when regular feeding schedules are nonfunctional. Flushing occurs when we feed our cannabis 1-3 times the volume of the container.  The water we flush our cannabis with is nominal pH water. Our cannabis flush rinses off nutrients, salts, and may drown insects, and alter the environment for microorganisms. Further, after we flush our cannabis we water them with a micro dose of nutrients. Often, cannabis leaves may droop after a flushing, a sign of overwatering.

When we water our soil the water pH is between 6-7 range.  Thus, when our runoff water is a pH value of 6-7 alterations are inappropriate. Whereas, is our water runoff is under 6 we provide our cannabis a pH of 7 the next watering.  When the soil runoff is a pH of 7 we provide our cannabis a pH of 6 next watering.


pH and hydro

We always wear food safety gloves in order to not contaminate the garden.  When acquiring a sample of our cannabis pH from the reservoir we use clean containers and avoid any unnecessary contact with the water and light exposure.

The mindful cannabis gardener understands pH maintenance in a hydro system is critical.  Cannabis system failure can and does occur abruptly with an inappropriate pH.  Thankfully, monitoring our space ships warp core is easy.  We monitor our reservoir.  Importantly, always micro dose the reservoir.

The mindful cannabis gardener observes pH of the reservoir and understands our bubblers which oxygenate the water will increase pH values.  Further, pH adjustments occur as cannabis feeds on the nutrients.  In order to control for pH challenges, nutrient challenges, nutrient lock out, salt build ups, algae, and bacteria we engage in water change outs.  Hydro water change outs occur every 1-2 weeks as appropriate.

Measurement pH kit

Captain Sunshine is familiar with such kits as similar to testing a pool.  Such as, using drops which change in color revealing the pH level.  We use a sample of water and add a couple drops of testing solution to the water to determine the pH in relation to the color.

Digital pH testers

We will need calibration fluid  in order to maintain an accurate pH reading.  Therefore, we need “4.01” and “7.0” solutions in order to calibrate our digital pH tester.

The mindful cannabis gardener also invests in storage solution.  Storage solution assists in driving down long term costs by increasing the life span of our testers.  Captain Sunshine standard operating procedures requires the cannabis gardener to use storage solution on the cap of the tester before storing our pH reader.  Further, the mindful cannabis gardener invests in cleaning solution as able.  Accordingly, cleaning solution will extend the life of our tester and increase long term savings.