Bleach is used for the source of chlorine for the pool. You will use it for daily chlorination and also for "shocking" the pool if that becomes necessary. Just plain, unscented laundry bleach. Many of us buy Walmart's generic brand. Read the information suggested above by Janet. Post testng numbers when you get them and we will advise you what to add.

Go ahead and buy several jugs of bleach and some 20 Mule Team Borax (laundry aisle at Walmart) and a box of baking soda as these are things you are likely to need right at first. Also, a small bottle of cyanuric (or isocyanuric) acid, which is sometimes called stabilizer or conditioner. (Buy the smallest container of cya that you can find.) You will most likely have to buy that at the pool store but everything else you can get at Walmart. Just don't let the pool store tallk you into buying anything else!