Measuring nitrogen using TDS meter ?

[Evendozen]

Thanks for all the great info Ray.

And to Joe-- your way is most likely how I will use the meter.

[Orchid Whisperer]

Following Ray's comment, EC will vary a lot with factors such as the water quality you start with, aand the type of fertilizer. Ray's numbers (above) for added K lite would probably be different using reverse osmosis water than for tap water from Chicago or Atlanta.

Also, it would be different if you used a non- K lite fertilizer blend. If your tap water is fairly consistent in quality, you could work out the concentrations with a calculator (see Ray's website).

[estación seca]

TDS of 268 is fine for a lot of orchids. Only the cloud forest ones, and a few others, would need water more pure than that.