Hi and welcome to the Pool Forum!

You really need to get a good kit. We don't put faith in test strips and the CYA test strips are especially bad. The kit we recommend is the Taylor K-2006 or 2006C (better buy) that you can get through the test kit link in my signature below.

We really need to know your CYA level to be able to give good advice since needed chlorine levels are based on the CYA reading.

By the way, a vinyl pool does NOT need calcium even though pool stores like to tell you that they do so they can sell you stuff to raise it!