I don't want to beat that proverbial dead horse, but some of the plant growers here employ low light, non-CO2 methods. For us, EI is not an option, as Tom has stated. To state catergorically that testing is a waste of time sort of marginalizes those of us who use it when we suspect a problem. (Sob, sob.)

If I switched to a high light, injected CO2 environment I would use EI and probably never see a test kit again. But I have enough trimming to do in my tanks as it is, without making the plants grow even faster.

I'm now off to remove the last gambusia from what is presently a fairly attractive, heavily planted tank. We'll see.

Bill