I thought I explained all of this to you the other day. Maybe someone else. But you should not use glass covers over your tank. Reguardless of the light you are useing. The glass covers hold the heat in your tank. You will have other thing producing heat in your tank other than just your lights. Your powerheads, pumps, filters. If it has a motor to run it, and water flows over or around it. It will warm up your water. It is just that simple. Think of your tank as a living thing. Because basically that is exactly what it is. And like all living things, It naturally does things to take care of itself. Whether you like it or not. Most people want the keep the glass tops on thier tanks to
1. Keep fish from jumping out of the tank, which is easily fixed with eggcrate.
2. To keep the water from evaporating so quickly. This will cause big problems. Your tank evaporates, (sweats) to rid itself up built up gases, and heat. Holding them in your tank can throw the tank off balance. Just like you, if on a hot summers day, if your body can not sweat to release heat your body will overheat, That is when you develope heat stress, or even worse heat stroke. I am not saying your tank will suffer from heat stroke. But it is the same idea. Never, Never use glass tops on a saltwater tank. The glass tops or normally made at the factory that makes these tanks and then ship them out the the pet stores like *****, or Petsmart. They are intended to be used for freshwater fish. That is also way they do not come reef ready. If you ever order a reef ready tank, (these are designed for and intended for use with saltwater) these do not come with tops on the tank at all. That is because they know that you are not suppose to use glass, or acrylic tops on a saltwater tank.
