Which nutrient formula is stronger in strength?

Hello All!

Gotta start somewhere and this whole ppm business has me all confused. Not to mention that my math skills suck!

Anyhow, if I'm showing a ppm of 400 on a meter that converts the EC by .5 (the one I own), and another ppm of 400 on a meter that converts EC by .7 (the one my nutrient formula uses), which solution actually has more nutrients in it? The .5 solution or the .7? Assuming of course that the water is the same amount, and the nutrient solution is the same strength.

And lastly, how do I convert a .7 formula to a .5 formula and please give me an example. Again, my math skills suck!

Thanks for your time!

bump....it would sure be nice to get someone to answer at least part of these questions.... thanks!

Get an E/C meter.All those directions on the back of the bottle are close figures and are not 100%.You can still tell how much nutes your plant is using by watching your ppm's.If the water is the same and nutes same strength your going to be ball park close.If your asking wether to go with the ph pen or what the back of the bottle says I say stick with the ph pen and convert from the ph pen not what the bottle says.
as for a conversion formula,I havent a clue,I bought an E/C meter