Confusion over ppm and ml

[aquarius]

From the treads in this forum, the recommended amount of fertilizer to add is all in ppm but the seachem ferts dosage are in ml. So how do i convert the ml in the instruction to the desired ppm.

eg K : 10 - 30ppm (recommended)
Seachem's directions : Add 1ml for every 40L of water. This dosage raises K by 1mg/L.

How do i know from this example that i attained the desired ppm?

[vinz]

Simple. 1mg/L = 1 ppm.

So effectively, Seachems directions is the same as : Add 1ml for every 40L of water. This dosage raises K by 1ppm.

But do not confuse ml with ppm.

[aquarius]

Thanks Vinz for enlightening me cos I was begining to think that ml and ppm is the same. Wah like that very expensive to dose seachem.

For a 160L tank i'll need to dose 4ml of K just to get 1ppm!