Does the PH really matter?
Nutrient availability is pH dependent so it definitely matters. Cannabis can tolerate a wide pH range, but does best between 6.2 & 6.8 in soil/less media and 5.8 – 6.0 in hydroponic media. There are two pH’s that matter; that of the water going into the system and that of the root zone. Measuring the pH of the root zone can be difficult in soil/less media since the probes often require that a media-water slurry be made. The pH of the runoff water is often measured as an estimate of the actual acidity/alkalinity of the medium. In my experience, this estimate is good enough. How do I measure pH? The best way is a wateproof digital pen. These are typically accurate to 0.1 or better and cost anywhere from $20 to several hundred dollars. Hydroponic growers need this accuracy as the pH range is much more narrow than that of soil/less media. Dipsticks can be had that change color for comparison against a chart. They typically have an accuracy of about 0.5. pH paper, also sold as nitrazine pap
