ppm 500 or 700? And your nute manufacture uses what conversion ? 500 or 700? If you can answer those two without a hitch then yeh go for a change in pen but its negligible. Or throw out plants because of burnt tips... But I don't really think that's a good idea.
Some pics would be cool
note - What's the difference? The ppm 700 scale is based on measuring the KCl or potassium chloride content of a solution. The ppm 500 is based on measuring the NaCl or sodium chloride content of a solution and is also referred to as TDS - total dissolved solids. Individual nutrient ions have different electrical effects! The true ppm of a solution can only be determined by a chemical analysis. ppm cannot be accurately measured by a CF or EC meter. They are present on Bluelab products as a conversion guide only. The conversion is as follows:
2.4EC x 500 = 1200ppm (500 scale) or 1200ppm / 500 = 2.4EC
2.4EC x 700 = 1680ppm (700 scale) or 1680ppm / 700 = 2.4EC
Manufacturer Scale
Advanced Nutrients 700 scale Botanicare 700 scale
CES/Cutting Edge Solutions 500 scale
Dutch Master 500 scale
FoxFarm 700 scale using dechlorinated tap water
General Hydroponics 500 scale using reverse osmosis water
General Organics 500 scale using reverse osmosis water
House & Garden 700 scale
Humboldt Nutrients 500 scale
Rock Nutrients 700 scale
Technaflora 500 scale
Some pics would be cool
note - What's the difference? The ppm 700 scale is based on measuring the KCl or potassium chloride content of a solution. The ppm 500 is based on measuring the NaCl or sodium chloride content of a solution and is also referred to as TDS - total dissolved solids. Individual nutrient ions have different electrical effects! The true ppm of a solution can only be determined by a chemical analysis. ppm cannot be accurately measured by a CF or EC meter. They are present on Bluelab products as a conversion guide only. The conversion is as follows:
2.4EC x 500 = 1200ppm (500 scale) or 1200ppm / 500 = 2.4EC
2.4EC x 700 = 1680ppm (700 scale) or 1680ppm / 700 = 2.4EC
Manufacturer Scale
Advanced Nutrients 700 scale Botanicare 700 scale
CES/Cutting Edge Solutions 500 scale
Dutch Master 500 scale
FoxFarm 700 scale using dechlorinated tap water
General Hydroponics 500 scale using reverse osmosis water
General Organics 500 scale using reverse osmosis water
House & Garden 700 scale
Humboldt Nutrients 500 scale
Rock Nutrients 700 scale
Technaflora 500 scale
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