As a doctor I am a beleiver in general that "less is better" . IN OTHER WORDS IF NOT SURE , DO LESS. Remove less water if not sure as it is less tressful then tking too much in general . Obviously there are some people that need a lot taken off , but if you are otherwise ok then less is better. Its safer to be less agressive . Overtime you begin to se how this works. Sometimes we try to do too much and beat up patients.