Stabilizer is kind of like 'sunscreen for your chlorine.' Without it, your chlorine will disappear fast especially on a hot, sunny day. Sometimes it is called conditioner. The real name is cyanuric (or isocyanuric) acid. You may have to buy it from a pool store (don't let them talk you into anything else!) or sometimes you can find it at Walmart, Lowe's or Home Depot. Buy a 5 lb. container. Don't add any until you get your CYA level tested. The pucks and possibly the shock you've added may have already added some stabilizer so we need to know the cya level before advising you how much additional to add. This is something you don't want more of than you need in your pool! What was the ingredient on the bag of shock that you added? Good decision to get the good kit. Hopefully you'll get it quick!