Look into a salt water chlorine generator.
Basically, you add 99% pure salt (water softener solar salt) to the pool to bring it up to 3300 parts per million (same as human tears). That's 10 times less salty than the ocean, and since its the same concentration as human tears, you can open your eyes in it.
The salt water runs through the filter, through the generator, and back to the pool. An electric current in the generator converts the salt into chlorine, and sanitizes the pool. That type of chloring reverts back to salt. Since salt cannot evaporate, it stays in the pool, whereas normal pool chloring evaporates with the sun.
You never have to add chlorine to the pool with this method. I've been using it for about 5 years and have never had to shock my pool, except when a squirrel committed suicide in it!!! I just used chlorine bleach from Walmart for that.
My typical costs for pool chemicals for the past 5 years has been about $40.00m per year. That's two bag of salt $10.00, 4 gallons of bleach $12.00 and two bottles of chlorine stabilizer about $15.00. I'm very happy with it.
It does use electricity, but I only run mine for 4 hours a day. The filter runs about 7 hours per day.
And one more side benefit of a salt water pool.... its soft water! You get out and your skin is soft, your hair is soft, blonde hair doesn't turn green and you suit dosen't fall apart at the end of the year.
I highly recommend it.