This month, a bursting pressurized pool filter knocked a Surprise man unconscious, sending local rescue teams to his aid. He had been cleaning the filter incorrectly, and then his family heard the blast and found him with critical head and chest injuries.

That accident worries emergency squads because it was the second of its kind in recent weeks, Surprise Assistant Fire Chief Kevin Pool said.

All pool filtration systems operate under high pressure and are potentially dangerous, Arizona State University pool technician Joe Zimmerman said.

Zimmerman explained some common safety tips for pool pump and filter use.

• Do not rely on instruction manuals alone when caring for your own system.

"See a video, or get training from a technician. There is nothing like hands-on training or a firsthand experience. Directions are vague at best and a lot of people don't understand the terminology," Zimmerman said.

• If you have a pool and spa, take extra caution.

"Some people go ahead and turn one (filtration system) off and think they've taken care of both, but usually it doesn't. If not, the pressure will keep pumping, pumping and boom," he said.

• Protect your pool filter.

Many people leave pool equipment out in the sun. Ultraviolet rays deteriorate the PVC plastic that a lot of filters, pipes and pumps are made from, he said.

• Look at your pool filter.

Most systems have a backwash, or multipart valve. This must remain in the proper position during normal pool use to prevent excess pressure from building, Zimmerman said. He suggests contacting a pool technician to learn more about specific models.

• Look at your filtration clamp.

Most filters have an O-ring or clamp. "If this is not on tight enough, pressure can build up and it could blow," Zimmerman said. Again, he suggests contacting a technician for questions about different models.

• Pools need checkups, too.

"It doesn't hurt to have your filter, pump and heating system, if you have one, inspected annually," he said.

Reproduced with permission from: The Arizona Republic By Erin Zlomek ©Copyright 2003 Arizona Republic