The weather is cooling down, the mosquitoes are quelling and the days spent in the backyard swimming pool may be less frequent. But that doesn’t mean it is safe to stop adding chemicals to pool water, balancing its pH and running the water pump.
“A lot of people, especially a lot of our winter residents, think the best thing to do is drain the entire pool and shut it down for the season,” said Clay Shagena, owner of Arizona Pool Drain.
However, the intense Arizona sun can cause plaster pool surfaces to dry out and crack, even in the winter, he said, though the pool surfaces that have the texture of pebbles, common in newer pools, can be left alone for the season.
“You really shouldn’t leave a plaster pool empty for any duration of time here in Arizona,” Shagena said.
For pool owners who are looking to save money on operating costs for the winter but don’t have a pebble-surface, it is safe to run the water pump during the cooler season for about half as long as in the summer months, he said.
According to APS, running a pool pump for eight hours a day instead of 24 hours can save about $72 per month for household energy costs.
It is crucial to keep the water pump running continuously when freezing temperatures are predicted to prevent pipes from breaking, but those circumstances are rare in the Valley, Shagena said.
However, if faced with a situation where the pool absolutely cannot be maintained, it is better to drain the water than let it sit untreated, Shagena said.
“A lot of people are forced with draining the pool and leaving it to the elements, he said. “Especially the poor folks in the process of losing their house.”
A swimming pool that has been left with its water standing still and hasn’t been treated properly can start to grow algae, which makes the water look very green or black.
“The longer they sit green, the more damage it does to the entire system,” Shagena said.
Shagena cleans up about 250 green pools a year, and about 70 percent of those pools have started to grow black algae, “which is pretty much a cancer diagnosis for a pool,” he said.
“It’s an eyesore,” he said. “Nobody likes to see a green nasty pool.”
Maricopa County doesn’t care how attractive a residential pool looks, but it is concerned with possible public health risks created by green pools, especially the threat of West Nile Virus, said Johnny Dilone, Maricopa County Environmental Services spokesperson.
There were two deaths related to the West Nile Virus in Maricopa County in 2012, according to Maricopa County Department of Public Health, and according to Arizona Department of Health Services, there were 80 probable and confirmed cases of the virus in humans.
In an attempt to combat the West Nile Virus, Maricopa County Environmental Services visits homes that were reported to have green pools on the department’s complaint line, Dilone said. The department received 4,289 complaints about green pools as of Nov. 4 in 2012, but there were less than last year.
“I believe the number has probably increased in terms of green pool compliance,” Dilone said. “People are more into making sure they are complying.”
Environmental Services will not clean a green pool, but needs to make sure there aren’t mosquitoes breeding in the water, Dilone said. If mosquito eggs are found in the water, the homeowner needs to start running the water pump again because mosquitoes cannot lay eggs in moving water, he said. If the owner cannot run the pump or the home is abandoned, Environmental Services puts mosquito-eating fish into the green pools.
There is less mosquito activity and the department stops getting as many mosquito-related complaints going into October and November, but the type of mosquito that is most likely to carry West Nile Virus does not go dormant in the winter, Dilone said. Mosquitoes can also still lay eggs that will hatch and create a bigger mosquito problem come March and April.
“We try to make sure people understand that it is something that is most likely happening all over the county, to make sure there is no mosquito breeding and health risk in the county,” Dilone said.
Environmental Services advises first talking to neighbors who may have a green pool about the risks, but complaints can be made by calling (602) 506-6616. Complaint numbers for specific cities, which may also have aesthetic codes having to do with green pools, can be found at https://www.maricopa.gov/ENVSVC/Complaints/Forms/ComplaintInput.aspx.