Use this useful tool to convert solution concentration choosing one of the 11 units of measurment included in this app (with the availability to add custom units), that are:
kilogram/liter, gram/liter, milligram/liter, part/million (ppm), grain/gallon (US), grain/gallon (UK), pound/gallon (US), pound/gallon (UK), pound/million gallon (US), pound/million, pound/cubic foot, gallon (UK).
For every units of measurment are also included formulas to convert that unit as you want.