Swimming Pool: Draining and Refilling

By April 14, 2019 May 16th, 2019 Cleaning & Maintenance
swimming pool, pool troopers


You’re probably wondering if a swimming pool should be drained of water and then refilled with it again. Pool Troopers has some answers to this question and information that might be helpful. There are a host of important reasons to not remove the water from the pool until it is necessary to do so.  It is normal that after five to seven years of use, pools should be drained of water, acid washed or bleach cleaned and fresh water added.  In some western markets that time frame is even shorter, three to five years, due to the hardness of the source water.  These drains and cleans are not only for the pool water but for the pool finish which gets metal and mineral deposits on it over time and can use the washing to get that fresh clean look again.   

If you are seeing pool that has been neglected, and water that looks murky, there are several steps that you can take before draining the pool. There may be chunks of algae floating around and there is decaying organic matter in the pool form dirt debris and critters.   Instead of screaming and feeling frustrated and getting ready to drain the pool, read further and learn more about when it is really time to empty that pool and refill it. 

Why shouldn’t the pool be drained? 

NOTE: POOL TROOPERS never suggests homeowners drain their own pool, ever.  Hire a licensed professional with insurance, including workers compensation and pool popping as well as local knowledge of rules regulations and groundwater conditions. 

One of the first dangers of emptying the pool is from hydrostatic pressure. It surrounds a filled pool and is built up from the groundwater that pushes on the bottom and sides of the swimming pool. 

Because a hole has been excavated and the pool placed inside this hole, there is backfill that has placed next to the virgin earth. This backfill is less dense than the surrounding earth and collects water, creating pressure while pushing on the sides and bottom of the inserted pool. Since that pool has been inserted and filled with water, the pressure that results from a pool filled with water is then in balance with the groundwater that is surrounding it.

When that pool has been drained, there is no longer water to push back at the groundwater pressure that has been created; the result is that the pool can float up on this groundwater and float right out of the ground like a boat on a rising tide. 

Hydrostatic pressure can:

  • Cause the floor of a concrete pool to shift and crack
  • Cause the pool to float and lift right out of the ground taking the decking a plumbing with it ruining your back yard and perhaps your home’s foundation

You may have a valve that is called a hydrostat. You can find it in the deep end side of your pool in the main drain. One way to combat hydrostatic pressure is to open this valve and allow some groundwater to come up from underneath the bottom of the pool. When this valve is opened up, there is some relief from the pressure than ensues after drainage of the pool.

If a pool is drained, groundwater around it will need to be removed, usually with a sump pump. The bottom line is that before hiring a contractor to drain your pool, make sure they are licensed to do the work, have adequate insurance for workers comp and general liability as well as pool popping insurance if you live in a high ground water state like Florida. 

Another reason not to drain the pool is that it leaves the floor and walls vulnerable to exposure from wind, rain and heat. Because the materials are meant to be submerged in water, there is danger.  In Arizona summers for example pool finishes will iterally blister off the pool if left exposed during the hot summer days.  So pools in that market are drained in the cooler months of the year. 

When it is really time to drain the pool 
Most pools need to be drained of their water and refilled with a fresh supply about every five to seven years, according to The Pool Master; it is time when the (TDS) Total Dissolved Solids reaches over 2500 ppm. When this happens, it will become difficult to balance your pool water to create a healthy environment. More chemicals will be needed. 

As time goes by, it becomes more difficult for regular maintenance to take care of the organic waste that has built up. Chemicals that have previously worked will no longer be effective. At this point, the pool, if in-ground, should be drained and refilled; when to drain will depend on your how frequently the pool is used, your maintenance schedule, and the type of environment in which your pool is located.


Call in the professionals 
When it is really time to drain the pool, professionals should be hired. You may have significant repairs that need to be done, and an empty pool is necessary. A professional can tell you whether the pool must really be drained to complete those repairs. Or if five to seven years have passed, and it is time for the pool to be drained, a knowledgeable professional should be called. If the pool is drained improperly, it can cause damage, so it is worth investing in expert know-how to get this job done. 

Pool Troopers can help you keep your swimming pool clean, before algae starts swimming around in the pool. Our cleaning services come in a variety of choices to fit your budget and needs. You might want the addition of our maintenance service, which offers a choice of visits and procedures. We have your back when it comes to keeping your pool in pristine condition for the enjoyment of your family and friends throughout the year. 

Pool water that has not been maintained can cause damage to the surface of the pool. Hard water can lead to deposits of calcium, which may cause damage to the grout and tiles of the pool. In the long run, it is cheaper to maintain the pool than to repair damaged tiles and finishes that have been destroyed by calcium buildup. 

We can clean and service your pool or spa on the same day of the week, allowing you and your family more time to enjoy the pool. Repairs are also part of our services, so Pool Troopers can consult with you to discuss whether draining your pool is a necessary step.

Give Pool Troopers a call to find out how you can keep your swimming pool in top condition with our services to help get it clean, so draining is not an option to be considered before it is necessary.