Hard water containing magnesium, lime along with other alkaline materials leaves a nutrient film on any surface in which it sits for a time period or is allowed to dry by evaporation. This includes your spa. Gradually cleaning this residue before it forms large, unsightly deposits known as scales enhances the durability in addition to the look of your spa. Removing light residue from your bathtub can be carried out quickly and inexpensively using common household substances.
Drain your spa.
Wipe the bathtub dry using a cleansoft cloth.
Pour a mixture of 50 per cent vinegar and 50 percent water into a spray bottle.
Spray the tub’s surface area with the vinegar solution and allow it to sit for 15 minutes. Pay particular attention to the waterline where nutrient buildup will focus.
Remove the solution using a clean moist cloth.