You're off to a good start. Your CYA is probably zero. It's also known as stabilizer, and it's something you have to add manually. Without CYA the sun will burn off your chlorine very quickly. You mentioned you are having algae problems, so this is also probably responsible for a lot (maybe most) of your FC loss.
You'll need to test your combined chlorine (CC) level to determine if there's something organic like algae which is causing problems. Unfortunately it doesn't look like your test kit includes it. Please consider getting a TF-100 test kit from tftestkits.net or a Taylor K-2006C. They're more expensive but they come with larger quantities of chemicals and they can test your CC levels.
While you're waiting for your test kit to arrive, please review the "ABC's of pool chemistry" in the Pool School link on this site. It's a quick read. Then you'll want to bring your CYA and chlorine up to recommended levels, and if you have algae you'll most likely want to go through the "SLAM process" (also described in the pool school).
Once your algae problem is cleared up and your chemicals are at the recommended levels, continue to test your FC. CC, and pH about once every day or so, and the other tests (TA, CH, CYA) around once a week. You may want to do some research on this site to see whether it's worth getting your auto-chlorinator up and running. You might be better off manually adding chlorine or investing in a SWG.