When Can You Heat a New Pool


So you’ve filled up your swimming pool and are excited to jump in, but the water is cold. You have a feeling that turning on your water heater isn’t the best idea. Well, you’re right, but how long you have to put off heating your pool is longer than you probably think.

You can heat a new pool after 30 days of filling if it has pool plaster and after 14 days if it has pebble technology lining. Either way, the swimming pool cannot be heated or used immediately. Water circulation and pool chemicals are required to keep the water from stagnating.

In this article, you will learn more about the best practices of having a fresh pool. It covers the waiting period before heating and the duration of water circulation. Among other things, you will also discover whether pool chemicals affect plaster and pool lining. Let’s get started with the main question.

When Can You Use the Pool Heater on a Brand New Pool?

A pool heater should be kept off for the first 30 days after you fill up a new pool and circulate water in it. This allows the pool plaster to cure. If you use pebble tec instead of pool plaster, then the waiting time is 10 to 14 days.

Pool plaster generally takes 30 days to cure once the water starts circulating in it. Pebble lining takes less time but depends on the manufacturer and its manufacturing material. In the case of pebble plastering, you should get the exact waiting period confirmed from the pebble lining seller.

Why Can’t You Heat a New Pool Immediately?

The reason you have to wait any period is to let the new pool lining get settled. In the case of plaster, you need the plaster to fully cure. Regardless of material, hot water isn’t the best contact material for fresh pool lining.

This can be tough because it takes two days to fill up a pool. After that, you have to circulate the water, monitor the acidity of the pool, and avoid swimming in it. All of this is to let the pool lining set.

Managing a Pool After Plastering: The Best Practices

A swimming pool is built and not acquired as a pre-manufactured product. It isn’t the novelty of the pool that makes heating it immediately a bad idea. It is the fresh plaster that is too vulnerable to hot water. Here are the best practices for managing a pool after fresh plaster.

  • Fill the pool as if it is swim-ready – Don’t fill half the pool with water. Fill it to capacity and norm. 
  • Add pool chemicals to avoid contamination – Pool chemicals generally protect the swimmer. But in the initial phase, the chemicals keep water from becoming too acidic or basic and kill microbes that might otherwise multiply.
  • Test pool chemicals more often – While the plaster is curing, the water pH will rise. You cannot preemptively neutralize that by having extremely low water pH. When the pool pH is low, the water starts eating away at the plaster.
  • Do not swim in the water – Any dirt in the water gets baked into the plaster in the first two weeks. The water is also not balanced enough to accommodate swimming. Avoid jumping into the pool while it is fresh, even if you can handle a cold dip.
  • Run the filter pump without turning on the heat – Water circulation makes it harder for mosquitos, insects, and microbes to thrive. A large body of still water is a magnet for diseases. You should run the pool pump for 8 hours a day.
  • Keep pets and dirt out of the water – Your dog is no exception to the “no swimming” rule during the plaster curing phase. Any dirt on your pet’s paws or in his fur can get lodged into the plaster and permanently stain the pool walls. Dirt, whether carried by a pet or by air, is bad for a fresh pool. 
  • Use a pool cover and brush the pool regularly – It is crucial to use a pool cover so that unnecessary dirt and debris don’t get baked into the pool walls. You should also brush the pool twice a day to remove dirt and debris.

How Soon Can You Swim in a New Pool With Pebble Tec?

Pebble Tec is a plaster alternative that features cement and pebbles as a lining solution. It is tougher than plaster, chips far less, and has half the waiting period.

You should avoid swimming in a new pool with Tec for only 14 days from filling and circulation of water. During this period, the water should not be heated, and its chemical balance should be monitored more closely.

While pebble tec takes less time to cure and be heat-ready, it isn’t any less vulnerable during this period. You need to handle your pool lining with care regardless of the lining material you use. It might bother you that you’re unable to swim in a pool you’ve filled up and are maintaining, but be mindful of the consequences of swimming in the pool too early.

What happens when you swim in a fresh pool too early:

  • Skin Rashes – Whether the pool pH is too high because of plaster or low due to the pebble tec, a swimmer will experience this adverse effect. 
  • Pool lining gets stained – Depending on how much dirt you carry, your pool lining will incur stains ranging from a yellowing tint to clear dirt marks.
  • Stinging in the eyes – This is an effect of acidic water, which is expected from diving into a pool with Pebble Tec within the first two weeks of setting the pebble lining.
  • Dry skin and itching – This effect is more prominent when swimming in acidic water than in cloudy alkaline water. Neither condition is good for your skin.

How Long Does It Take To Heat a 20000-Gallon Pool?

It takes 2 to 4 days to fill a 20,000-gallon pool and 13 hours to an entire day to heat it. Accounting for this, one can assume that a fresh pool has the following resting period:

  • 4 days of filling, 30 days of resting, 1 day of heating: 35 days maximum. 
  • 2 days of filling, 14 days of resting, 13 hours of heating: 16.5 days minimum.

Jed Arnold

Jed spent every year from the ages of 15 - 22 as a Lifeguard (Red Cross) and ages of 17 - 22 as a Certified Pool Operator (CPO). Between working for over a dozen facilities and owning a pool, he carries over a decade of pool experience.

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