Wow nice tank. The size is great with plenty of room for the opae to grow and breed. You need to keep in mind that the algae feeds off the waste that the opae & MTS produce. I think there's something off in the tank since the macro algae should not have gone bad that soon. Granted my tanks have been up for some time there's plenty of opae in them to support the algae. One of the tanks I just let the macro algae grow any way it wants. There's probably more than 500+ opae in this one.