[shilala]

The green algae grows when the water is too fertile. So does brown algae and all the other crap. She was probably topping off with tap water.
To do the reef thing, you absolutely have to have a source of zero tds (total dissolved solids) water, Scotty. That means it's completely pure. Then there's nothing for the algae to grow on.
I get lazy and don't test my water from my unit and I can tell the filters are shot as soon as algae blooms. Some amount is acceptable, but not much.

I don't think I'd start scrubbing anything. Move the tank, make new water (even if you have to buy distilled by the gallon at Target), and get a Tang. Tangs love eating that algae, they'll clean it right up, but slowly. That's what you want.
If you start scrubbing the rock you'll do more damage than good.

You'll probably need new lightbulbs, too. Depends on what kind of fixture she has. Just clean the filters and skimmers and do proper maintenance.
The new, clean water will likely starve the green algae and make it break down and sluff off slowly. The Tang would keep up with that and you won't have a big nasty bioload for the filters and tank and water to take care of.

After the initial setup, you'll need to change about 1/3 of the water once a month.
Then start reading your brains out. It only took me 15 years to get from a saltwater rock/fish tank to a successful reef.
Reef tanks need specialized equipment that I didn't have quite right (lights and wavemakers, mainly). Once everything is right, it's easy. About as hard as taking care of a cat.