Sol, How long has your tank been up with the cooked rocks? I think in the beginning you will see no algae for a while but as time goes by unless you actually stop what is adding the excess nutrients you will never stop algae from coming back.
In my last tank setup I get a bunch of algae very quick and tried everything, I had 0 TDS, HUGE skimmer, very light feeding, rinsed all food, etc and could never find a way to get rid of the Algae. Well after going through the entire setup and still not finding anything that could cause I started working backwards on my system and I realized that I had not replaced my RO/DI filters in a while. Now I was still getting a 0 TDS from them so I thought they were fine. I still didn't trust them so I replaced all the filters and within 2 weeks of doing that and a couple of water changes the algae was gone. So, I guess they were adding something to the system that was creating the algae.
Rich