Buy a master test kit for reefs, you may however have to buy one or two test that do not come w/the master. You need the following: ammonia, pH, alkalinity, nitrate, nitrite, calcium, and phosphate. Also, you MUST use R/O D/I water for reefs. If you don't, your corals and other inverts won't make it. You can buy a decent one for about $75.00 on that famous auction site. Any other questions???? A word of advice. More often than not, some fish store employees either have no idea what they are talking about or have little knowledge about reefs. I'm saying this from personal experience, and by reading the threads on here that say, "The guy at my local fish strore said....." I'm not saying they're all wrong, just don't draw a conclusion from one person's advice...ask around. In this hobby, you will find that if you ask 10 different people the same question, you'll get 10 different answers. So like I said, ask around. If someone gives you advice, ask two or three other "experienced" reefers if it's true or if they know about it. It can be very confusing at times :notsure: Good luck and you're off to a good start by asking questions. When I started, there were no sites like this, and when I was your age, I had to walk to school barefoot in five feet of snow and my school was seven miles away