In order to take control you need a quality test kit. You were either using a pool service or pool store. Either way, the good kit costs less than one month service or one trip to the pool store. It will pay for itself dozens of times over. You need a TF-100 from tftestkits.net or a Taylor K-2006C available many places online. Either kit needs a k-1766 added to it for salt. Also get a smart stir. It does all the mixing for you and sounds silly but is the best $30 you can spend on your pool. The TF-100 pro salt comes with all of the above.
Next up is download the poolmath app and setup your pool specs. Click on any parameter, FC for example, and enter your start and finish values and it will tell you what you need.