What are the correct ranges to maintain for cannabis cultivation?

When handling the stone wool right, important aspects such as water content (WC), electrical conductivity (EC), and pH, can easily be monitored and adjusted when needed. The reason these aspects have to be closely looked at is their heavy influence on crop health, growth, and development.

There are several things that can be adjusted to influence the WC, EC, and/or pH in the stone wool, such as irrigation amount, schedule, and the given nutrient recipe. This is what we called steering the crop with irrigation and stone wool offers this wide range of control.

About the Water Content

What concerns the WC, thanks to the high water retention of stone wool, more water can be held for a longer period of time compared to other substrates. As well it is easy to increase WC which has a vegetative effect or decrease WC which has a generative effect on crop development. Usually over the crop cycle the WC in the root zone will be between 50% and 90% depending on the crop stage and plant development. Important aspects in relation to daily WC level are cycle size, amount of cycles per hour, start & stop times and the decrease in WC during the night. This we will discuss in depth in future articles.

Balancing the EC and pH

By adapting the nutrient composition of the fertilization mixture the EC (mS/cm) and pH can be affected. When EC levels are too high, osmotic pressure around the roots increases, making water uptake more difficult, and when the pH is not within the preferable range, meaning too acidic or too alkaline, struggles such as lack of nutrient availability for the crop to uptake can result in nutrient deficiencies and damage the growth and development of the plant.

Therefore, it is important to make sure the pH of the nutrient solution is around 5.5 to 5.8, which is a pH range that allows nutrients to be taken up by the plant. What concerns the EC of the nutrient solution, the preferable level depends on the growing stage the crops are at; for cannabis propagation, the optimum EC is 1.5 to 2.5 mS/cm, while for the vegetative to flowering stage it is 2.4 to 3.0 mS/cm. Nevertheless, it is important to understand the difference between the EC of the stone wool, and the EC of the irrigation solution, both should be measured and monitored. The range of the stone wool EC can go from 3 to 6 mS/cm without it damaging the crop. Steering the EC in the substrate is done by the gift EC, moment of 1st drain and amount of drain.

Efficiency is key

Full control over WC, EC, and pH maximizes resource efficiencies, which increases sustainability and reduces costs. Measuring these aspects in cultivation is important, therefor please check in following articles how to do correct measurements for WC, EC, and pH.

Want to know more?

On this website you will find more information on our stone wool substrates and instructions for optimum use! If you have any question, remark, or request, please feel free to contact us here, or via our Facebook and Instagram accounts.

More items

interview samer abilmona greenleaf medical2

Discussing Substrates, Operations, and More; Interview with GreenLeaf Medical

GreenLeaf Medical started in 2017 and has grown tremendously since then, growing and selling a full range of products to the medicinal market within the USA. Samer Abilmona has been in the cannabis industry for a little over 10 years, but he has cultivated cannabis for the majority of his adult life. He has been the Executive Director of Cultivation and Operation of GreenLeaf Medical since 2019, then the company consisted of one cultivation facility, started to work on the second, had one dispensary in Maryland, and recently received a license in Virginia. Nowadays, the company is a multi-state operator, with facilities in Virginia, Pennsylvania, and Maryland. The cultivation is tailored to their market leader, smokable flowers. Other products within their range are live resin, live rosin, and distillates for vape cartridges as well as for edibles. About 6 months ago GreenLeaf Medical merged with Columbia Care, now the Cannabist Company, Samer has been managing a few additional cultivation and extraction facilities in West Virginia, two facilities in Washington DC, and a second Virginia location.

cultiwool channeling

Understanding and Mitigating Channeling in Stone Wool Substrate

Stone wool substrate has gained popularity in horticulture due to its excellent water retention and air porosity characteristics, which are essential for healthy plant growth. However, one common issue that growers often encounter when using stone wool is channeling. Channeling refers to the inefficient distribution of water and nutrients within the substrate. In this article, we will explore what channeling is, what typically happens when it occurs, how to identify its signs, and discuss methods to prevent it. We will also delve into why some stone wool products are more prone to channeling than others and explore the role of binders and wetting agents. Finally, we will touch upon the importance of choosing the right irrigation system to avoid channeling.

20200504 170143

What is Slag Wool and How does it Differ from High-Quality Horticultural Stone Wool?

As more and more products and companies become available on the market, it is always important to do a little research. Not only on the company itself but how the products are being produced. A little bit of research and asking the right questions can save money and time, but maybe the most important, the crop and your investment.