Create a cleaning paste by mixing baking soda with water. Apply the paste using a non-abrasive applicator, such as a sponge. Make circular motions as you scrub the entire surface of the hot tub. When it's clean, rinse the tub with water.
Remove any calcium accumulation with white vinegar. Mix the vinegar with water to make a cleaning solution that will dissolve areas of calcium buildup.
Clean your hot tub filter every month. Remove the filter and spray it down with a garden hose. Be sure to direct the water stream into the filter pleats to wash away clogs and dirt.