I assume you're taling about adjusting the water height in the skimmer column (cylinder).The height of the water return pipe on the right (facing it) is adjustable. See where it exits from the cylinder. Loosen the retaining ring and gently move the pipe upward to raise the level in the cylinder. Then, re-tighten the ring and you are set. My biggest problem is that I frequently have to clean the Rio pump it came with.