Reef Aquarium Deep Cleaning

I have a reef aquarium that has been set up for several (4) years now. I clean at least weekly, perform a 10% water change weekly, but now the water i remove is green from algae, but no obvious particulate algae. Water conditions are good with low nitrates and phosphates. So this got me thinking about a "deep cleaning" of the tank. Do people do this? Are there guidelines for how?



Thanks.



Rex