Every swimmer wants clean pool water, free from the algae you can see and bacteria that you can’t.

That has meant treating the water with chlorine, which not only kills any unwanted organisms, but also burns eyes and makes hair feel like straw. That is, until now.

A grant from the Maine Department of Environmental Protection has taught some of Maine’s busiest pools to reduce their use of chlorine by more than half, cutting the exposure to swimmers and the environment to what the federal Environmental Protection Agency calls an extremely hazardous chemical.

The biggest danger is for people who use the pools. Exposure to chlorine can result in skin irritations and lung ailments, as a result of breathing water vapor in the air around pools. Exposure to chlorine has been connected a higher risk of allergies and asthma. It can cause serious damage to the digestive tract if swallowed, and will kill animals and micro organisms if the pool water is released.

For the Portland YMCA, the answer to cutting back on chlorine use was just adding an enzyme to the water to cut the level of phosphates.

Now they have been able to reduce their use of chlorine by 60 percent, down from up to seven gallons a day. It not only makes the swimmers more comfortable, it also saves money.

DEP is still studying the effect of reducing chlorine on air quality at pools, and if the results bear out what the people who use to pools have reported, it could be expanded to set a standard for all of the state’s more than 750 public and private swimming pools.

There is no point in using a chemical intended to keep people from getting sick, if it just makes them sicker in other ways.