How to test the pH level in your hydroponic or soil plant growing system

Why is the pH value of the growing medium of a cannabis plant so critical?

Because a cannabis plant will only absorb nutrients from the growing medium when it is marginally acidic, with a pH of between 6 and 7.

Those vital nutrients include nitrogen, phosphorous, potassium, calcium, Sulphur, magnesium, iron manganese, boron, copper, zinc and molybdenum.

Interestingly, cannabis grown hydroponically or without soil requires the pH level to be slightly lower again, at between 5.5 and 6.5.

The question you all probably are now asking is how do you measure the pH value of the growing medium?

Well, the good news is that it is not as complicated as you may remember from chemistry lessons at school when you spent most of the lesson trying to blow the building up.

First, you can buy digital pH meters from between £10.00 and £20.00, though some find it a little fiddly trying to calibrate them.

To test the pH, simply plunge the needle of the meter into the damp growing medium.

An alternative is to use a pH kit with drops, which takes a little longer, but is not complicated.

Mix some soil with distilled water which has a pH value of 7 so will not skew the result as 7 is neutral,

neither acid nor alkali and then add a drop of the pH indicator, and the colour of the water will change.

You then compare the colour of the indicator against a chart to show you the pH value of the soil.

Third, you can use pH paper which works similar to pH drops.

Rub some of the growing medium on the palm of your hand, then wipe it clean. Do the same and add some distilled water, then touch the water with the pH paper and it will change colour.

Once again, you then compare the colour of the indicator against a chart to show you the pH value of the soil.

Don’t panic if the results are outside the range you need, as you can buy products to easily adjust the pH of your growing medium.

Which method do you prefer? Let us know in the comments box below.

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