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when swimming’s done for the day, an alarm can stand sentry over the pool

Sounding an alarm: when swimming’s done for the day, an alarm can stand sentry over the pool

Why are alarms important?

While there’s no substitute for adult supervision, alarms provide a second set of “eyes” around the pool. When used properly and consistently, alarms can effectively serve as a backup to other safety barriers.

What type of alarm is best for me?

First and foremost, you’ll want one that meets ASTM safety requirements. After that, you’ll find a variety of alarm options on the market today that vary in cost (from $70 to more than $6,000) and complexity. In general, the alarms are designed to detect motion around the pool, or movement at or beneath the water’s surface. Most alarms come with the option of a remote receiver, which allows the sound to be heard inside the house or at greater distances from the pool area.

Door/gate alarms

If your home opens directly out to the pool area, a door alarm will provide some added protection. Your home’s security system may already feature alarms on the doors and windows. Otherwise, you can install a separate system to monitor the key entry/exit points that lead to the pool.

You may also want to add an alarm to reinforce the security of the pool fence’s gate. With these alarms, two magnetic switches are mounted directly on the gate. When the gate opens, the electrical field is interrupted and an alarm will sound. Typically, there’s an override button or pass code that can be pressed, allowing adults to pass through without setting off the alarm.

Pool-perimeter alarms

Similar to a motion detector, pool-perimeter alarms are engineered to send out a warning signal before your child even reaches the water. These systems consist of devices that send out either a laser or infrared beam, depending on the manufacturer. The beam bounces off two mirrors positioned at the corners of the pool and is then sent back by a reflector, creating a four-sided invisible fence. If someone/something passes through the beam, a warning sound is produced. The height of the beam is adjustable so you can modify it to fit your needs. However, the systems don’t distinguish what crosses the beam, so the occasional raccoon scuttling through the pool area may set off the alarm.

Surface alarms

When it comes to surface alarms, there are two different options: One style attaches to the pool’s edge; the other floats in the water. These alarms typically feature a sensor placed below and above the waterline that detects disturbances on the water’s surface. If the sensor above the waterline gets wet due to an object falling into the pool, it triggers the alarm.

However, the alarm’s sensitivity needs to be taken into consideration because both a child and a toy falling into the pool can displace water–the alarm may sound for both. Because these alarms rest on the water’s surface, they can’t be used with covers. These devices are portable and battery powered (most come with a low-battery indicator).

Subsurface alarms

Most subsurface alarms attach to the pool wall and extend into the water. They detect changes in the wave patterns under the water, and are designed to sense if an object greater than 15 pounds has fallen in. Because the sensor is located below the waterline, false alarms due to wind or rain are typically kept to a minimum. Also, they can be used while the pool cover is on. Some advanced models incorporate both subsurface and perimeter options, doubling the product’s protection zone.

Also on the market is an underwater system that uses sonar technology. The device sends out sound waves underwater. A child falling in will disrupt the sound waves, causing the system to send an alarm. The product has been engineered to differentiate between the wave pattern created by a pool toy or a child. The device can be used on a variety of pool styles, even vanishing-edge models. While it uses state-of-the-art technology, its steeper price–it retails for approximately $5,000-plus–may stretch your budget.

Personal immersion devices

To keep track of individual children, you can use water-sensitive, battery-operated wristband alarms. The device is securely locked on the child’s wrist, like a watch. If the device gets wet, a sensor triggers a warning to a receiver, which can be placed in the home. If you’re concerned about your pets, there’s a device on the market that looks similar to a collar.

What should I ask my pool professional about alarms?

Does the alarm meet ASTM standards? You need to be sure the device has been thoroughly tested and can meet strict safety standards.

Will my pool’s design affect the alarm’s effectiveness? Some alarms may work best on pools of a specific size and shape. If your pool is particularly large or calls for a variety of special features that stir up the water, such as vanishing edges or waterfalls, you’ll want an alarm that can work well under those conditions.

Has the alarm been tested for reliability? An alarm often is the last safety barrier between children and the water. It’s important to know that it works all the time. Ask if its performance has been evaluated to ensure that it will work consistently. In 2000, the CPSC studied the efficacy of various pool alarms; visit to view its results.

What about false alarms? People have come to ignore the sound of car alarms because they’ve earned a reputation for going off for no reason. Similarly, you will be less likely to respond to a pool alarm if it sounds without cause. Check to see what the alarm’s track record is and if steps have been taken to reduce false alarms.

How loud does the alarm sound? Can the volume be adjusted? Some alarms are available at different decibel levels. Testing the volume will ensure you’ll be alerted quickly, without knocking the socks off neighbors a mile away.

Word to the wise

* Test your alarm regularly to ensure that the battery is fresh and the sensor is working properly.

* After swimming, remove or secure all toys and other objects that could be blown by the wind into the pool. This will keep the items from accidentally setting off the alarm.

* Never prop open gates or doors–this will negate any of the alarm’s benefits. And always look to make sure the gate closes securely behind you.

COPYRIGHT 2004 Hanley-Wood, Inc.

COPYRIGHT 2004 Gale Group