Help, algae bloom

Question
QUESTION: Hi, i work at a petco and am the fish specialist there. I am having a very bad algae problem in the show tanks and was wondering if you could help me with some knowledge. I have vaccumed the crushed coral numerous times and to no avail. i have used maracyn-plus as a algae killer because it was suggested, but to no avail. I have cleaned the crushed coral two days in a row and changed 50 per. of the water and changed the filter media but the algae comes back. The algae is green and like a film, i have started to see brown algae also. what could i do, please helpppp. what could i do? Please give me several suggestions if you could.

ANSWER: How new is the system? Also what kind of lighting are you using, also what kind of water tap or reverse osmosis?

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QUESTION: The system is about 10 years old and has been this way(with the algae) for about three months which is when i began working there. Regular florescent lights and regular dechlorinated tap water. No r/o sys.

Answer
There is a petco right outside of my place of employment. They seem to have the same problem the person is constantly scrubbing the aquariums. I stop there in the morning sometime, and they are cleaning all of the time. Try using a phosphate remover and see if it will get it under control, also have you tried some other ways. Such as crabs, snails etc.