Watermom is correct, but I didn't want to overwhelm you just yet. Still the $50-$70 you spend on the K-2006 will be the best investment you make in your pool. We all use either that or an equivalent kit. Still, when things settle down you'll use the little yellow and red kit for your daily testing and the full kit once a week.

Ultimately, it will all come down to 3 things:

How much chlorine you put it, using mostly just bleach. This is to keep the water sanitary.

What the pH is and how to adjust it. This is to keep the water from being to acid or alkaline and irritating skin and eyes, or even damaging the pool.

How much stabilizer you have, which acts like sunscreen for chlorine, but also slows the chlorine's effectiveness down. The level of stabilizer determines the level of chlorine you need.

That's it. That's ALL pool maintenance comes down to. Sanitation and pH--and things that affect that.

Carl