Welcome to the forum!
Do you have your own test kit? Can you post a full set of test results? What chemicals have you added? What does your water look like?
Can you fill out your signature? The type and size of pool along with your equipment helps us help you.
I suggest you read ABC's of Pool Water Chemistry.
Chlorine is a consumable item. Unlike things like Calcium Increaser that stay there until they get splashed out, chlorine gets used up killing algae and bacteria and germs and by sunlight. If your water isn't stabilized, any chlorine you add will be gone within hours. Even stabilized properly, it will be gone in a couple days. And that's in a crystal clear pool. Even if it was fresh tap water to start with.
There is so much information here it will make your head spin. Start with the ABCs of Pool Water Chemistry so you at least understand some of our lingo