The first thing you do with any algae is clean it out of the tank and off of the plants. If any plants are heavily infested with algae it is best to prune away the algae. Then change at least 50% of the water and get the CO2 up to 30 ppm and fertilize adequately with NPK and traces. You are likely to battle some algae for quite awhile with that high a light intensity, so it would help to turn off half of the light until the algae is under control and you are dosing fertilizers steadily. Make or buy a drop checker - the Red Sea unit is only about $14, and works fine, but you need to use distilled water with a KH of 4 dKH in it, not tank water. Then you will know you have 30 ppm of CO2 in the water when the water in the drop checker is green.