When Should I Drain My Swimming Pool?

Home/When Should I Drain My Swimming Pool?

Pools require a lot of maintenance, but luckily, they do not need to be drained very often. However, there are a few circumstances in which it is necessary to completely or partially drain your pool. These reasons usually have to do with water quality or repair needs.

When and Why a Pool Should Be Drained

Most pools rarely need to be drained. Because the process of draining a swimming pool without damaging it can be difficult, the experts have figured out ways to do most necessary work without removing all of the water. However, there are a few reasons why you might have to drain your pool:

  • Total dissolved solids levels
  • Certain types of repair work
  • Refinishing and/or repainting

Total dissolved solids (TDS) are substances that accumulate in the pool water over time. Eventually, they cause water chemistry to become very unstable. This means more and more chemicals are required in order to maintain your pool water within the correct parameters. However, it is not always necessary to drain the pool entirely to deal with this problem.

If your pool requires certain types of repair work or refinishing, we will take care of the drainage process. This is often the best idea, because draining a pool improperly can damage it. If you will be repairing or refinishing the pool yourself, be sure to educate yourself on the process for your specific type of pool.

What Time of Year is Best to Drain a Pool?

Depending on the type of material that your pool is made out of, exposure to the elements may damage it. Because of this, the best time to drain your pool is when the weather is mild. If the temperature will be over 85 degrees at any point in the process, it is best to postpone. The same is true of temperatures near or below freezing.

Because of these temperature parameters, the best time to year to drain a pool is usually in the spring or fall. Spring can be a good option, because the fresh water will then be ready for summer swimming. Fall can work, too, but most professionals do not recommend letting your pool remain empty over the winter, so you will need to at least partially refill it.

Why You Should Periodically Drain Your Pool

The single most important reason to drain your pool is to deal with TDS levels. When TDS levels get too high, they start to interfere with the chemicals at work keeping the water sanitary and clear. More and more chemicals are needed, which can be harsh on the skin and even damage the pool itself. Eventually, a point is reached where the water cannot be maintained properly no matter how many chemicals are used.

Most professionals recommend draining your pool every three to five years in order to keep TDS levels low. How often your pool needs to be drained depends on a number of factors, including overall use. If the pool is partially drained every winter, this dilutes TDS levels and will extend the interval between complete water changes.

How to Drain Your Pool

Before draining your pool, the groundwater levels should be considered. If water levels in the area are high enough, they can actually cause your empty pool to pop out of the ground. In addition, fiberglass and vinyl liner pools require special treatment because they are typically not built to be drained entirely. Completely removing the water from these pools can cause bowing or cracking of the surface.

Once you have assessed the groundwater situation and the needs of the type of pool you have, the safest way to drain your pool is to use a submersible pump. These can often be rented from pool supply companies or hardware stores. While the filter pump can be used to drain a pool, this runs the risk of damaging an expensive piece of your pool hardware.

Usually, pool water must be drained into the sewer outlet on your property. Sewer lines are not built to deal with huge quantities of water all at once, so the outflow should be kept to approximately 12 gallons per minute or less. Completely draining a pool with a garden hose can take a day or more. In most cases, it will then need to be at least partially refilled, so you can plan on the process taking a couple of days to complete, at the minimum.

There are several reasons that you might need to fully or partially drain your pool. However, it can be a big task and doing it improperly can result in unwanted consequences. A little planning ahead can save you from a big headache later.

What are the risks of improperly draining your pool?

There are a few:

  • The pool can heave out of the ground
  • Sun and exposure can damage your pool
  • You can damage or burn out your filter pump
  • You can back up the sewer system into your home

Your pool heaving out of the ground is a serious problem that may occur if the groundwater level in your area is high. This might be the case all of the time, or only after several days of heavy rain. The problem occurs when your empty pool starts to float on the groundwater and be lifted out of the ground.

Empty pools are also susceptible to damage from exposure. Vinyl pools tend to contract when emptied, which can result in damage when they are refilled. Gunite or fiberglass pools can crack, and fiberglass pools may suffer bulging or splitting if drained. It may also void your warranty to drain your fiberglass pool.

If you do not adjust your filter, pool pipes, and waste lines properly, you run the risk of damaging or burning out your pool’s motor. This can happen if the gallons per minute (GPM) of your pump exceeds the ability of your waste line to handle. It can also happen if the filter sucks in air and ends up running dry.

Most municipalities do not allow you to dump pool water just anywhere. The approved location is usually your sewer system. However, putting too much water into your sewer system all at once can result in it backing up into your home.

When to consult a professional

If you are not 100 percent certain that your pool needs to be drained, you should consult a professional. Many pool repairs can be done underwater, and many problems with the water can be treated rather than requiring replacement. If you do not know what the water table is in your area, or you are not completely certain that you know how to drain your pool, you should also consult a professional.