I have some questions about cleaning a hot tub. I have recently drained my tub and will be refilling it this sunday, before i drained it, I was told by the Hot Springs dealer to put a half a bag of burnout 35 ( a shock for pools) run for 45 mins then drain. I have some stains on bottom of tub in 2 areas, can I use white vinegar to clean off safely , dont want to hurt tubs surface, stains are minimal and were caused by adding well water without filter attached to hose. My question is, what procedure should i do when draining and refilling the tub. I have allways done it according to the dealers, but what is the best way to prevent bacteria buildup in plumbing lines, etc.. Just looking for a wealth of information on drains and refills, thanks .