Hello Ken and welcome to TFP! The PoolMath APP is a great tool to help you with recording testing results and understanding the effects of adding certain chemicals. Take a few moments by using the menu icons to update your user "pool" profile. From there you can begin to load certain pool preferences. Once you are ready to load test results, you should see the + symbol which will allow you to add test results or other items. If you get stuck on something specific, post back and others will be happy to guide you.