Hot Tub Drain Schedule Calculator

How It Works

Even with perfect chemical maintenance, hot tub water accumulates dissolved solids, body oils, lotions, and other contaminants that chemicals cannot remove. The industry standard formula for drain frequency is: Volume divided by (Bathers x Uses per Week x 3). A 400-gallon tub used by 2 people 4 times a week should be drained roughly every 17 days. Signs that you need to drain sooner: foamy water that will not go away, persistent cloudiness despite proper chemistry, strong chemical smell, or difficulty maintaining balanced water. When draining, take the opportunity to clean the shell, flush the plumbing lines with a pipe cleaner product, and clean or replace the filter.