What causes cloudy hot tub water?

Cloudy water in spas can be due to many different things, including poor filtration, low sanitizer levels, and poor water balance.

Poor Filtration

Very often, cloudy water is blamed on poor water chemistry, and more chemicals are added to try to clear it up. However, the most common cause of cloudy water is poor filtration. This can be due to not cleaning the filter frequently enough, not running the pump enough hours, and not preventing obstructions to circulation in the spa. If the cartridge filter is not being chemically cleaned periodically, oil and dirt build up on it that rinsing does not remove. Dirty filters cannot properly remove insoluble waste. Clean the cartridge periodically with SpaGuard® Filter Cleaner and Degreaser, and rinse off debris weekly. Stain and Scale Control and Water Clarifier can be used to aid in the removal of smaller particles that the filter can't always get.

Low sanitizer level

Low sanitizer levels can allow bacterial growth. Even if the sanitizer level only drops temporarily, at that point, bacteria can gain a foothold. After some bacteria multiply, it takes more than just regular maintenance levels of a sanitizer to keep it in check. Test your sanitizer level frequently. If the sanitizer level drops, even for a short period, shock the spa with Brominating or Chlorinating Concentrate to increase the sanitizer level and help eliminate more prolific growths of bacteria. After shocking, if you still cannot maintain normal sanitizer levels, see the instructions for bacterial growth.

Buildup of undesirable compounds

If the spa is not being shocked often enough, the compounds that enter the water from bathers and other outside sources begin to build up. The filter can't remove all of this waste, and it is usually too much for the sanitizer to remove. Shocking with Spa Shock or Enhanced Shock will help eliminate these compounds.

Poor water balance

High Total Alkalinity, pH, and /or Calcium Hardness can cause cloudy water. Adjust the water balance according our ALEX® Pro recommendations.