For the gravel part I just disturb and syphon, then I turn over the gravel somewhat especially at the front of the tank it, the algae, forms little clumps which adhere to the gravel and are easily removed. All should come clean in the end. It is a long process though and patience is definately the key on the salty side. My tank is set up nearly a year now. I'm overhauling it by adding a sump (something I should have planned for in the begining but didn't) I am only at the edge of adding my first corals due to algal issues, I need to get the tank with virtually zero algae before I go spending big doh on the corals. Purple rockwork, 2 clownfish, crabs and snails is all that I have to amuse me, oh yeah I almost forgot...a helluv a lot of maintenance. I've used a large bucket of salt mix for waterchanges already and not a coral in sight.
I hope the sump and a DI unit coupled to my RO system will be the holy grail.
LOL
Stick in there, I know its not easy but your not alone on this.
Regards
BigC