If you hire CMK Pools to maintain your pool, you might just want to check your chemical levels on your own. We found out the hard way that our pool guy was not adding chemicals and treating our pool. The first time this happened, the owner Chris was really good about making sure they paid to have our pool shocked and treated. We decided to continue to do business with them and give them another try. I was very disappointed last week to discover that once again, our 2 year old pool had no chlorine in it. I even had my husband run his own set of tests to make sure that mine were accurate. I was so upset that the same thing had happened again! Pool companies are a dime a dozen out here in Phoenix. I would look elsewhere before doing business with CMK pools.