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Nutrients & EC

What EC should I use for cannabis seedlings?

The answer is: 0.5 EC

A practical range is about 0.4 to 0.6 EC.

What EC should I use for cannabis seedlings?

Why

For cannabis seedlings in inert DWC or RDWC, a practical target is 0.5 EC with a working range of about 0.4 to 0.6 EC. That is total EC, including your starting water. Reverse-osmosis water may contribute almost nothing, while tap water can use up part of the target before nutrients are added. Begin mild, balanced nutrition as the cotyledons open and the first true leaves develop. Too much EC can create osmotic stress, tip burn, wilting, or stalled growth. Compare readings at the same water level after circulation so the trend actually means something.

What to remember

  • Target about 0.5 EC for seedlings.
  • Use roughly 0.4 to 0.6 EC as the working range.
  • Count the EC of your source water in the total.
  • Begin mild balanced nutrition as cotyledons open and true leaves develop.
  • Compare reservoir trends at the same water level after circulation.
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