Take it for what its worth but if it is an algae issue in the water column algae needs light just like everything else. Your corals and stuff will make it a few days w/o light so I would turn off the lights and wrap the tank in a blanket or soemthing so absolutely no light gets in for 2-3 days. When you unwrap the tank the algae should be gone. If its not an algae issue I wouldn't go that route Along time ago I had a bad algae issue in the water column but the water was more green then yellow.

As mentioned above a pic would help.