Draining your Swimming pool
Many people ask us why it is necessary to drain and refill the water in their pool.
The mineral composition of household water in the Phoenix area tends to be toward very hard water. Hard water is the term for the amount of calcium deposits in the water measured in parts per million (ppm). Many households install a water softener in their homes so that the hardness can be reduced by special filtration or salt. The benefits of softer water is less corrosive calcium deposits in the plumbing, water heater and plumbing fixtures, with an additional benefit of a more pleasant bathing and water use experience.
The water used for outside purposes such as irrigation and filling a swimming pool does not (usually) get softened by the water softener. When included in the plumbing system, contractors plumb a special “loop” that excludes these outside fixtures.
Swimming pools have a constant body of water that is open to the elements. The water originally used to fill the pool after construction is the external “hard” water provided to the home from the local utility department. The mineral content of the swimming pool water tends to increase due to:
- Improper chemical balance during the maintenance period can cause a greater chance of calcium hardness
- Evaporation – minerals do not evaporate and removing the water “liquid” increases the density of the minerals
- Rainfall and runoff cause water imbalances
- While water is replaced when evaporation occurs or when DE or Sand filters are backwashed; this water again is from an already hard water source.
The effects of hard water on a swimming pool
Calcium deposits can accumulate over time on tile, handrails, internal pool surfaces and can begin to clog valves, heaters and pool equipment. Items having large deposits of calcium over time have to be replaced or cleaned by scraping or media blasting using sand or glass beads as the usual media. Thicker deposits may not be able to be removed. Repair of damaged items can range from $500 to over $3500.
Other minor effects of overly hard water is related to the ability to maintain a chemical balance and water condition that ensures that the water is sanitized using the least chemicals as possible. Hard water also contributes to the swimmers hair and skin being dry after swimming.
Reducing the calcium in swimming pool water is a maintenance item similar to oil changes in a car or replacing a home water softener salt or filter.
The most cost effective and feasible way to reduce the calcium level is to drain the water and refill the pool. Most times, swimming pool owners opt for the additional services related to pressure and acid washing the pool surface and cleaning the pool tile of the accumulated calcium deposits.
In the Phoenix area, swimming pool water usually has to be changed out every 4-6 years and this mostly depends on the surrounding environment, the ongoing chemical balance of the water, the effectiveness of the periodic maintenance (of PH levels and Total Alkalinity) and most importantly the water calcium hardness measured in parts per million (ppm). The ideal range for Calcium Hardness in swimming pools is 180 – 220 ppm, although others may use 200-400 as an acceptable range of hardness. Water over the ppm reading of 400 indicates that water needs to be replaced. A reading of over 600 ppm indicates that it is critical for the water to be replaced. The more time water in this condition is kept in the pool, the greater the chance for an equipment failure or need to replace tile or internal pool surface.
Drain, Clean and Refill
The activities involved with the draining, cleaning and refilling process involve:
- Pumping out the water into the sewer drain-out. This is an access usually in the front of the home that is used for plumbing access and these types of draining activities. Draining water in washes is done only if absolutely necessary. Your pool technician will shut off the power to the pool equipment and turn off the autofill connection during the service period.
- Pressure washing the surface and using a diluted mixture of muriatic acid provide for the removal of most deposits on the pool’s interior surface. Care should be taken to dilute the acid correctly and apply it to the surface consistently. Failure to do so will leave stains and could cause the pebble surface to lose pebbles. Acid should be used with extreme care.
- Tile cleaning, while optional, will remove the deposits from tile and other surfaces. This is preferably done while the pool is drained, but can be done, at a greater cost, while the water is in the pool and during warmer weather. The cleaning involves a pressure source and media that will strip the deposits from the surface. This is an extra service and is optional at the swimming pool owner’s discretion. Deposits left on the tile will further accumulate not only calcium but dirt and suntan lotion type materials. This deposit covers the original tile color and is also a place for algae to accumulate. Tile cleaning is usually priced on the linear foot of tile to be cleaned.
- Rinsing the entire pool and preparing the pool for refill.
- Refilling the pool with the customer’s water usually costs in the $50 – $60 range.
- The pool technician will come out and restart the pool equipment and rebalance the water.
We try to secure the drain hose and take care of your property as much as possible. Your assistance in unplugging the pump when the pool is empty, or monitoring the filling of the pool is much appreciated.