Fluid, Electrolyte, and Acid-Base Balance. Fluid balance The amount of water gained each day equals the amount lost Electrolyte balance The ion gain each day equals the ion loss Acid-base balance H+ gain is offset by their loss. Body Water Content.
If ECF becomes hypertonic relative to ICF, water moves from ICF to ECF
If ECF becomes hypotonic relative to ICF, mater moves from ECF into cells