We'll need more info to be able to help.

Is this a freshly filled pool? What all have you used in the pool so far? Is your granular shock cal-hypo or dichlor?

Your kit is actually missing a couple of critical tests --- a CYA test and a FAS-DPD chlorine test that can read chlorine readings higher than 5ppm. Both of those kits can be purchased separately as add-ons and used in conjunction with your current kit. You can get them through this link which takes you to Amazon. http://pool9.net/tk/ The K1515 is the FAS-DPD kit and the K1721 is the CYA kit. They will cost around $50 together.

Whether or not you should be using trichlor depends on your CYA level. How much trichlor (tabs) do you have on hand? Are they individually wrapped or not?

What does your water look like? Have you had any algae recently?

I know I have asked a lot of questions but knowing these things will help us to better advise you.