4Meter LAQUAtwin KitA Lab In Your Pocket Measuring leaf and fruit sap ions with meters like the HORIBA LAQUAtwin is extremely important for all fruits and some vegetables. Sap measurements give a snapshot of the actual nutrients moving in the plant, not just whats in the soil. Soil tests alone are insufficient because nutrient availability can change daily based on water uptake, growth stage, and environmental stress. The LAQUAtwin meters can measure K, NO, Ca, Na, pH