Ask the General: What’s the Proper Winter Water Level for My Pool?

pool winterization

Dear General- We’re closing up our pool this week. (Insert sad face emoji here…) We want to make sure we do it right and we’ve gotten varying information about what the proper water level is for winterization. Can you set the record straight for us?

Waffling about Water Level in Wakarusa

Dear Waffling- You’re not alone in wondering about this and it’s one of the most important aspects of pool maintenance. Lowering your pool water can really cause some problems when Old Man Winter kicks it into high gear and Frosty the Snowman starts dancing across your pool cover. Here are some words of wisdom to guide you as you button up your pool for the winter.

First of all, it’s true that you’ll find conflicting information out there on the world wide web about the proper water level for winterization. Every pool company has its own opinions and of course, where you live matters. Here’s what I think: If you live in the Midwest, bring your water level down to just under midway on the skimmer, no lower than that.

When your pool maintenance pro comes to close your pool, he’ll probably use a device that is known as a “Gizzmo.” (Yes. That’s actually what it’s called.) The Gizzmo is a pretty cool pool maintenance tool that protects whatever type of skimmer you have AND helps maintain the proper water level through the winter. Here’s how it works:

Winter Skimmer Protection

When water freezes, it expands. The pressure of that expansion can crack your skimmer. The Gizzmo is designed to absorb the pressure from ice expansion to prevent it from destroying the skimmer. It can be used in both above and inground pools. Basically, the Gizzmo is absorbing the pressure so the skimmer doesn’t.

Winter Water Level Maintenance

The Gizzmo has a plug on the top of it that is left open while air is blown from the pump area through the lines, clearing them of water. Most pool maintenance pros will then pour a gallon of antifreeze through the opening and into the piping to ensure the lines won’t freeze. Once the plug is screwed on tightly, water can’t get back into the piping.

Why is Winter Water Level Maintenance Important?

All inground pools have a common enemy. It’s called groundwater. Groundwater can wreak havoc on every type of pool if you allow the groundwater level to rise above the water level in your pool. In the winter months, while you’re busy watching football and baking Christmas cookies, you need to be sure that your water level underneath your winter cover doesn’t get out of whack with the groundwater around your pool, or you might be in for a world of hurt (and expense) when you pull that cover off in the spring. Here’s what might happen, based on the type of pool you have:

Vinyl Liner Pools: On a vinyl pool, if the water level inside the pool becomes lower than the water on the outside, the result is something we refer to as “floating the liner.” It’s not a good thing. It means that the liner is wrinkled and damaged beyond repair. A pool maintenance pro will have to drain the pool completely and replace the liner.

Fiberglass Pools: If the pressure of groundwater exceeds the pressure of the water in your pool, your fiberglass pool shell might shift, crack, or float. In addition to properly winterizing your pool, having your fiberglass pool secured with the Geo-Anchoring Pool System is best the way to avoid this risk by reinforcing the structure of your pool.

Gunite Pools: Groundwater pressure can cause cracks in gunite pools over the winter as well, resulting in the need for resurfacing. Ceramic tile along the waterline can also be adversely affected. The worst possible case is flooding. If groundwater is not managed properly, a gunite pool can actually float.

What’s the takeaway?

winterizationProper winter water level maintenance is key for a happy pool opening in the spring. Try to keep your pool cover clear of debris over the winter so you can keep an eye on the Grinch known as Groundwater. One of the benefits of an automatic pool safety cover over a standard winter cover is the ease of being able to take a peek periodically at your water level.

Remember, your best bet is to maintain your water level to just below the midway point of your skimmer. Doing so means you’re most likely to keep your water level in balance with groundwater throughout the freezing weather and you’ll be back in the swim in no time in the spring.

Until next time – The General                

Who is The General?

The man, the myth, the legend….we just call him The General. His organized, systematic approach to pool installations over the years had his crew members calling him “The General” and it stuck. The General has over 30 years’ experience in the pool and spa industry, working for one of Pool and Spa News’Top 50 Pool Builders.”


Over that time, he designed, sold, project-managed and installed over a thousand inground swimming pools. As a pool owner himself, he’s the perfect authority to give you the inside scoop, with amazing tips and tricks to make pool ownership a breeze!

About Thursday Pools

Thursday Pools designs and manufactures the world’s most durable and elegantly crafted fiberglass pools. We are ISO 9001 certified, which means that fiberglass pool shells are made with the highest standards and from the best quality material available. We are also ISO 14001 certified, which means we are committed to environmental stewardship.

Our one-piece, inground fiberglass swimming pool manufacturing facility is based out of Fortville, Indiana. At Thursday Pools, we aspire to be the world’s most respected fiberglass pool manufacturer and to help our customers create a lifetime of memories with their family and friends. Our innovations, commitment to quality and beautiful designs set us apart. Thursday Pools is the creator of the world’s first beach entry (or zero entry) fiberglass pool. View our exclusive designs for the Grace Beach Entry design and the Sandal Beach Entry Design.

Get a free estimate on the fiberglass pool of your dreams today. With Thursday Pools, your weekend starts early!