anyone know TDS meter would help monitor nitrites or plant nutrients?

[alexfox]

I am a newbie. I know a lot on hydroponic.
I think may be TDS meter helps monitor nitrites.nitrates.

 

[Mebbid]

A tds meter will only give you a measurement of all of the dissolved organic and inorganic compounds in water. It won't give you specific compounds that are in the water so it isn't really very useful in freshwater applications unless you are filtering and mixing your own water.

There are some different pieces of testing equipment in salt water aquariums to test nitrates but I'm not sure if they will work in fresh, not to mention they are ridiculously expensive.