Adjusting the PH of the irrigation water in cannabis cultivation is one of the most important factors to achieve a good harvest
Let’s see how important it is to measure and correct the PH of the irrigation water to make a good cannabis crop and get a good harvest. Measuring the PH in cannabis cultivation helps us to control it and leave it at a level where the plants can absorb the fertilizers that we throw it, since these are of little use if the roots cannot assimilate them because the PH is too high or too low.
Some growers do not believe that PH in cannabis cultivation is completely fundamental. But most plant deficiencies come from an inadequate PH in the irrigation water. If we continue like this, we could end up modifying the PH of the substrate, which would imply more serious problems. If we water a few times without measuring the PH in a crop, for example once in 5, the plant will almost never notice it, because the PH of the substrate will be maintained, more or less, with the level you usually water the other 4 times. But if we water 4 times out of 5 with an inappropriate PH level, we will end up with the substrate at an inappropriate PH and it will be very difficult to adapt it to the correct level. That is why it is important to measure and regulate it from the beginning.
During the growth phase, marijuana plants need lower levels of PH than in the flowering phase. This is because the plant absorbs nitrogen much better with a PH of 6 than with a PH of 7 or 6.5. However, during the flowering phase the plant will need a pH of 6.8 or 7, because with these levels it better absorbs phosphorus and potassium, which are the most important nutrients during this stage.
It may seem that getting a little out of these limits in PH in cannabis cultivation does not matter, but it does. For example, if we water a cannabis plant with a PH of 8 during the growth phase, it will be yellowish, because it will not be able to absorb Nitrogen (N), nor Calcium. If we water a cannabis plant with a PH of 8 during the flowering phase, it will absorb only a quarter of the phosphorus and potassium, while with a PH of 7 it would absorb these nutrients almost entirely. And if the plant does not absorb them, they will accumulate in the substrate and you will have excess accumulated salts, which is another reason why plants stop eating and show deficiencies, such as small leaves, flowering delay and more.
And conversely the same happens. If we water with a PH only 1 point lower than the plant needs, the result of your cannabis cultivation can be mediocre. The correct PH in cannabis cultivation determines the difference between success and failure. We should not leave this to chance when we can correct it. The solution is to wash the roots with corrected water, a long and tedious process but necessary if we want to correct the inappropriate PH of the substrate in a cannabis crop, but that is what it needs to be done in these cases.
Fertilizers change the pH of the irrigation water a lot. Therefore, it must be measured after adding fertilizers to the water. In most cases, after adding fertilizers, the PH must be lowered, but in some cases it must be increased. Some growers use homemade products like vinegar or lemon to adjust the PH in a cannabis crop. But the crops in which these homemade products have been used smell bad. It is unpleasant that a crop smells like vinegar. And more when you can buy a bottle of liquid to adjust the PH that, in addition to being very durable, costs very little money. Homemade products are not worth it, and also, when you use them in a water tank or do not spend the water immediately, the variations in PH are large and it can happen, for example, that the water that today has a PH of 6, tomorrow has changed and the PH has risen up to 8.
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In specialized stores, such as growshops, you can find digital meters and chemical meters to measure the pH of the water. But it is much more interesting to buy a digital PH meter because chemical meters, when you use some fertilizers, change the color of the reaction, making the measurement unrecognizable. These chemical meters are worth to measure the pH of the water that we are going to use to do a root wash.
The PH table is an exponential, non-arithmetic table. What does this mean? The PH means “hydrogen particles” contained in the water. A water with a PH of 8, for example, has 10 times more hydrogen particles than a water with a PH of 7. Each point that we go up or down will involve ten times greater or lesser amount of hydrogen particles. Therefore, do not believe that between 7 and 8 there is only one point of difference, since there are 10 times more or less quantity of hydrogen particles. Between water with a PH of 7 and another water of 7.1 of PH there is only one point of difference between the amount of hydrogen particles. Therefore, it is of great importance to adjust the PH well in cannabis cultivation.