Learn your cannabis grow acronyms

Why are there so many acronyms for indoor growing? Man, it can get confusing!

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“I’m just adjusting my VPD to balance my RH and measuring my LST whilst LST training my plants. And also checking My PPF, which affects my DLI.”

I mean, these are long words, so shortening them makes sense. Try saying photosynthetic photon flux density (PPFD) 3 times fast without your brain melting out your ear.

So this week, we’re going over the super top-level meanings of some of the more popular acronyms and how they relate to each other for those that have yet to learn..

VPD, or Vapour Pressure Deficit, measures the difference between the amount of moisture in the air and how much moisture the air can hold when it's fully saturated. It guides how quickly plants transpire and absorb water and nutrients, affecting how fast they photosynthesise.

DLI, or Daily Light Integral, is the total amount of light a plant receives in a day, measured in moles of light per square meter, indicating the plant's exposure to beneficial light for growth. 

PPF, or Photosynthetic Photon Flux, measures the total amount of light produced by a light source per second in the photosynthetically active radiation (PAR) range. Plants can only use so much depending on their environment, so knowing this is key.

PPFD, or Photosynthetic Photon Flux Density, indicates the amount of light that actually reaches the plant or specific area, measured in micromoles per square meter per second. If you want an even light spread in your grow, measuring PPFD is where you need to start.

LST, or Leaf Surface Temperature, refers to the temperature of a plant's leaf surface, which can differ from the ambient air temperature and affects the plant's growth and health. This is not to be confused with low-stress training (also LST), which is a technique where plants are gently bent and tied to control their shape and promote even more light exposure and larger yields.

VWC, or Voumertric Water Content, refers to the amount of water available in the substrate. It’s used to influence plant growth phases and optimise yield and quality.

PWEC, or Pore Water Electrical Conductivity, measures the EC of the water within the pores of the substrate or media, indicating the nutrient concentration available to plants, also known as Substrate EC.

EC/TDS, or Electrical Conductivity/Total Dissolved Solids, measures water's salt content or mineral content, indicating its conductivity and the overall nutrient levels available for plants.

CO2, or Carbon Dioxide, is essential for cannabis growth, enhancing photosynthesis and plant growth when maintained at optimal levels in the growing environment.

RH, or Relative Humidity, measures the amount of moisture in the air compared to the maximum it can hold at a given temperature, which is crucial for managing plant health and growth conditions.

LED, or Light Emitting Diode, is a highly efficient lighting technology that emits light when current flows through it. Widely used in grow lights for its energy efficiency and ability to target specific plant growth wavelengths.

pH, standing for potential Hydrogen, measures the acidity or alkalinity of a solution on a scale from 0 to 14, indicating the concentration of hydrogen ions and affecting nutrient availability for plants.

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Have I missed any? I definitely have! Let me know.

All of these play vital roles in how we grow and the final results we get. When you’re growing indoors, you’re the one in the driving seat. 

If you’re not on top of all of the above (and more!), your yield and quality are going to suffer big time. 

Don’t get me wrong, you can grow great plants without knowing any of the above, but this takes years, if not longer, to master, and rarely is it repeatable every time. 

This is obviously just the tip of the iceberg, and we’ll go into more detail on each of these topics week by week. 

As mentioned a few weeks ago, I am big on creating the optimum environment for growing, so this is where the focus will be and what we will discuss the most on Grow The Best. 

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Happy growing!

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Theo

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P.S. Need any help? Have a question? Stuck on an issue with your grow environment? Contact me now.

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I will get back to you in 24 hours and I’m happy to help.

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