I think this is a simple problem to solve, but I keep getting nonsense answers. The question: two reserviors held at constant osmolarity (say 1000 mOsm/l) are connected by a semipermeable membrane. A current of 1 uA is measured across the membrane. What is the volume of fluid that must flow through the membrane? So I have 1 uA = 1 umol/s ion flow, and 1000 mOsm/l means that 1 umol of osmolyte corresponds to 10^-7 liters of solution. So, 0.1 ul of solution is transported per second. Is this correct? The reason I think I'm having trouble is that using my actual numbers (100 uA, 300 mOsm/l) I get very high fluid transport rates. Much higher than what is observed.