We made trials with self made biological fertilizer, and separated the fluid from the solid, the fluid contains a EC value of over 30 mS/cm.

However to bring it down to less than the recommended <1mS/cm, we need to dilute it by 30.

however, in that case we loose the concentration on N,P, K as well and the fertilizer effect is no more of a sufficient value.

Anybody has an idea, how to extract this high concentration with a simple process, which leaves the remaining nutrients inside the fertilizer. Are we talking here about salinity?
I guess that electro osmosis is not the right process, because it will filter the other nutrients as well.
Any idea about a simple to apply process?

thanks Marc