pH is crucial when it comes to a plant's well-being, but it can be a very tricky thing to understand. pH is a scale that indicates whether something is basic (alkaline) in nature or acidic. The scale ranges from zero until 14 with battery acid and lemon juice being the most acidic at one and lye being the most basic around 14.The letters actually stand for potential or power of hydrogen: when a hydrogen molecule is either increased or decreased than the value of the pH raises or lowers.
Seven is neutral on the scale and roughly the number at which you should be adjusting your water for your cannabis plants. The ideal range for cannabis plants is between a pH of 5.5 and 6.5, depending on the medium. With rockwool or cocos its best to keep your pH between 5.5 and six, this is because soil acts as a natural buffer absorbing both nutrients and pH.
It’s important to always check your pH before every feeding, as the value of your water could change from day to day. Things like evaporation and temperature are what create these fluctuations. It's also advised to check the pH of the medium you are using. For soil, purchase a soil pH reader and with hydro systems, drain off some water and test that, keeping in mind that llght effects your pH, which directly alters the way the plant uptakes nutrients.
Plants will absorb nutrients at different pH’s which is why its also a good idea to slightly fluctuate your levels between the above-mentioned scale. Nitrogen has the largest range of absorption of all the nutrients. It can be absorbed between a pH of 5.5 and eight. Phosphorus (P) is absorbed between 5.8 and 6.1 while potassium (K) is absorbed between five and six. The micronutrients all jump up the scale significantly, magnesium, which very important in sativas and in kushes, is absorbed from 5.8 to seven. While calcium is absorbed from five to 5.8.
The best thing to do is to really look at your plants and more importantly, to listen to them. Check your nutrient solution with your pH meter and make sure you change the values, lowering and raising your pH in the middle of your crop to allow better uptake of the P and K.
It is always important to keep a grow diary and i would definitely recommend writing down what you feed your plants and what the plant looks like from week to week. Compare that to the pH levels of your feed solution and you will get a clear picture of what your plants direct needs are.
Keep on growing!
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