How do you use a potometer

1) cut shoot under water (prevents air entering xylem) and at a slant (increases SA available for water uptake) 2 assemble potometer in water and insert the shoot underwater, so no air can enter 3) remove end of capillary tube from the beaker until one air bubble has formed and put the end back into the beaker 4) record the starting position of the air bubble 5) start stopwatch and record the distance moved by the bubble per unit time