Can I drain my pool and leave it empty for winter?

Many new owners ask this question and one of the reasons they give for asking this question is that they think the hassle of winterising the pool and maintaining it during the off-season sounds like too much work!

The answer to this question, no, it’s not okay to drain your pool and leave it empty! In fact, you really shouldn’t be draining your pool unless absolutely necessary!

We’re not saying that you should never drain your swimming pool, what we’re saying is that there will be situations where you will need to drain your pool but doing so to skip winter maintenance isn’t one of them! Here are the main reasons why you should drain your swimming pool.

• Periodic Pool Overhaul - Sometimes referred to as deep cleaning your pool. This is done once every five years or so. Even if you’re spot on with your pool maintenance routine and chemical balancing, there will become a point where your pool water just becomes “old” and it will become harder and harder to keep in check.
• To remove uncontrolled staining - Either from bad maintenance practices or just from time, draining of the pool will be necessary to perform a full acid wash or to do refinishing of the pool surfaces.
• Major Repairs - Minor repairs that can be done without draining the pool should be done without doing so. But for large repairs like plumbing repairs, large cracks, and the like will warrant draining the pool.

P.S. Draining your pool should be done under the supervision of a pool professional or a pool maintenance service for safety reasons.

Here are the reasons why we always recommend a pool professional to oversee draining the pool.

• Your pool can “pop” out of the ground - Depending on your area’s water table, an empty swimming pool can be pushed out of the ground by hydrostatic pressure. Which is just basically saying that the pressure exerted by the water/ground outside of your pool exceeds the pressure from the inside of the pool, causing your pool to get pushed out of the ground.

• Sun exposure damage - Your pool surfaces are designed to be underwater. Prolonged exposure to heat and sunlight will damage these surfaces. Concrete and gunite will dry out and crack, fibreglass surfaces can bulge or split, and vinyl liners can contract and turn brittle.
• You risk burning out your pool pump - any pool professional will tell you that to properly drain a pool, you will need a submersible pump. A pool pump will only work to draw in water if the levels are above the skimmer box. Once the water level drops under the skimmer level, the pump will start to draw in air and it will cause overheating and eventually pump burn out.
• You could be breaking the law - Depending on local laws, it may be illegal to dump out your pool water into the sewer system due to the volume. Again, consult with with your local pool expert and the authorities.
• You may cause sewage to enter your home - While this rarely happens, dumping too much water into your sewer system may cause it to back up and can cause water in your drains and toilets to rush back up into your home.

Once you’ve determined that draining the pool is absolutely necessary then one more thing to consider is the season. Since we already know that the elements can have an impact on your pool surfaces then it would be safe to say that the best time to drain your pool would be in the fall or in the spring where the weather is considerably milder than in full summer or winter. Avoid times where rain is on the forecast as this can delay your repairs and it can increase the pressure coming from the ground as well.

The downside of draining the pool during the fall is that the temptation to keep the pool empty during winter is high! And the longer the pool sits empty, the greater the risk is of damage to your pool. But if you’re really keen on doing repairs before the winter sets in then just be sure to refill the pool immediately after the repairs are complete, winterise it, and close the pool for the season.

Spring on the other hand is another matter. If you decide to drain the pool and do repairs in spring then once you have done the repairs and refilled the pool, you can actually start your swimming season early with the use or addition of a pool heater! Now that I think about it, this will actually work during the fall as well if you live in an area with relatively mild winters.

As much as possible, a swimming pool should remain empty only for as long as needed! Once the repairs are done then it should be refilled and rebalanced immediately. Most major pool repairs only need a few days, a week at the maximum to complete.

Just like the old adage that says measure twice, cut once. Always get a second opinion unless you absolutely trust your pool professional. Even if you think that at first glance a full drain is necessary, explore other options first as what may seem as a major problem can be solved without draining the pool.

• Uncontrollable staining requiring an acid wash? Try and consider doing a no-drain acid wash first to see if that can fix the problem.
• TDS Levels out of control? One way of how TDS can be effectively reduced is to partially drain the pool, refill and rebalance. Try that first before draining your pool completely.
• Spiderweb Cracks and Superficial Damage? If it isn’t a structural issue then you can probably hold off until you can do a major resurface renovation to save up on money.

Draining the pool should always be the last resort and not as a stop gap option to skip on basic maintenance tasks. Developing a good maintenance habit, no matter what season it is, winter, spring, summer, or fall, goes a long way to turning what seems to be a repetitive task into something that can actually be a pleasing experience. And remember, the more preventive maintenance you do on your pool, the less you'll spend on pool chemicals and the more you'll be saving on repairs.