- Sat Aug 26, 2023 11:08 am
Most of us don't use EC readings for measuring/estimating appropriate media, we use the more general TDS reading, which uses EC to determine it. Maybe TDS and EC are the same thing, two sides of the same coin. We buy the inexpensive TDS meters and shoot for ~ 50 ppm or less if the makeup of the water is unknown. Testing the runoff from media can give us an idea of how appropriate the media may be.
With coir, the coconut palms typically live close to the ocean and absorb a lot of salt from the spray and uptake from the roots. After harvest, it's generally observed that coir left in the open for three monsoon seasons will allow virtually all of that salt to wash away. However, most suppliers don't have the room to store coir for years, and, since it's usually added as a supplement to soils, there's usually not enough salt to cause a problem for regular plants, and most of what's left is likely flushed out in the first watering. Obviously, carnivorous plants are not regular plants.
The reason that a strong suggestion exists to rinse coir well is due to this absorbed salt. I know a few growers that love coir, and their only complaint is that it sometimes takes days, if not weeks, of soaking, rinsing, testing, and repeating to get the TDS down to an acceptable level. Most of them will do that with tap water, with a final few flushes of rain or distilled water to get the runoff down to almost 0 ppm TDS.
Everything happens for a reason. Sometimes the reason is that I make bad decisions.