Drain, Clean, & Refill. We thoroughly clean the entire hot tub. First we remove the old filter & add a specially formulated tub and line cleaning solution (additional charge) to the water and thoroughly circulate it. Then we scrub the shell, cabinet, & cover. Once it is clean to satisfaction we drain the old water out completely. We then flush out the tub and all the plumbing lines. After all this we vacuum out the tub, wipe it down, and refill with fresh water. This process is done very comprehensively and professionally. It takes considerable time to do it right. Since we do such a thorough job we have many customers that request this service quarterly over and over again. Service available in CT only. After check out one of our representatives will contact you to schedule this service.