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Mastering EC & PPM for Healthy Cannabis Growth

If you grow cannabis, you’ve probably heard the terms EC & PPM. “PPM.”

PPM” stands for “parts per million,” and it is a unit of measurement that describes the amount of Total Dissolved Solids (TDS) in a solution. EC stands for electrical conductivity. These are acronyms used in the hydroponic industry related to measuring nutrients or “salts” in the water or mediums that plants grow in.

When growing cannabis, you should do EC measurements to make sure your plants are getting the perfect amount of nutrients. If that sounds too technical, don’t worry – it’s really simple, and you’ll learn all the most important information in this article.

Before Start growing cannabis, you should learn what is TDS/PPM?

1ppm is equal to 1mg of dissolvable material per liter of water – a tiny unit of measurement. For reference, most tap water in Thailand contains somewhere in the range of 300-500ppm, means the tap water in Thailand have 300-500mg of dissolvable material per liter of water.

PPM is the unit of measurement. What you actually measure is the total amount of dissolved solids in your nutrient solution, and this is found by testing the electrical conductivity of the liquid. A solution with more minerals in it, conducts electricity better.

The Importance of Measuring TDS/PPM for Growing Healthy Cannabis

To make sure you are keeping your plants healthy and well nourished, you need to measure the PPM of all the water you give them and also the PPM of your plants’ runoff water. This information will allow you to correct your nutrient levels and avoid over or under nourishing your cannabis.

How and When to Measure TDS and PPM

When you are ready to water your plants, always start by mixing the nutrients and then adjust the ph. Once this is done, check the ppm of the solution. You should do this every time you water your plants and record the data somewhere for reference.

You only need to check the PPM of your runoff once a month, but some people like to do it more often.

The PPM measurement of soil runoff will be much higher than coco. Since soil is made up of many different elements, these will be added to the total measurement.

This does not mean that the soil is over-fertilized. When measuring soil runoff PPM you’re looking for trends and not the exact amount of nutrients in the soil. Big changes in the data are what you need to worry about. 

Understanding Your TDS Readings

If you want to taste your waters runoff, give them clean water until you have some runoff water. The runoff water’s PPM reading should always be lower than the irrigation water’s reading. This indicates that nutrients are being absorbed by your plants.

However, if the PPM value of the runoff water is really low, it means that your plants probably need more nutrients than you are giving them.

If the PPM value is the same between the nutrient water and the runoff water, this is a sign that your cannabis is not absorbing nutrients efficiently. This is sometimes caused by sudden changes in pH. If the runoff water has a higher PPM than the nutrient water that means that there is probably a buildup of salts around your plant’s roots.

To fix this, you can run a high volume of water through the soil in a short amount of time to dissolve the salts and carry them away. This is called “leaching” or “flushing,” and we recommend that you use twice as much water as the volume of the container your cannabis is in.

To grow the best cannabis, why is it Important to Know the PPM of Your Tap Water?

Not all water is the same – it’s not just H2O. When we talk about ppm (parts per million), we’re diving into really tiny measurements. Depending on where your water comes from, you might need to tweak it before giving it to your plants. It’s crucial that your tap water is below 200 ppm before you add anything.

If your tap water has too many ppm, you can bring it down by using carbon filtering, distillation, or reverse osmosis. If those methods don’t do the trick, you can try using a nutrient mix that’s not as strong and is made for hard water. So, keep an eye on your water quality – your plants will thank you for it!

What TDS Level is good for grow healthy Cannabis?

Cannabis plants nutrient needs vary over the different stages of their lives:

  • Seedlings don’t need any nutrients; just PH adjusted pure water.
  • During the first half of the vegging cycle, they’ll want water with a ppm of 600-750 (EC 1.2 – 1.5).
  • During the second half of the vegging cycle, aim for 750-1100ppm (EC 1.5 – 2.2).
  • During the early-flowering, increase to 900-1100ppm (EC 1.8 – 2.2).
  • During the mid-flowering slight decrease to 750-900ppm (EC 1.5-1.8)
  • During the end of the flowering stage reduce to 600-750ppm (EC 1.2-1.5)
  • Finally, reduce to 0-300ppm (EC 0-0.6) as you flush your plants in preparation for harvest.

EC & Ppm Conversion Chart

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