Although the kit came with some things I will never need, it also came with everything I will need, plus a very clear explanation of how to keep my water chemistry balanced. It is definitely a starter kit (for people with large spas, several things will need to be replenished fairly soon -- and the test strips are really only sufficient to get you through setup, no matter the size, so order more test strips!) but if you are new to spa maintenance, the instructions are really nice to have as a reference.