Green hair Algae

I have a 55 gal. salt water tank. It is a combination of corals and a few
fish. Lately I have been having a problem with green hair algae and I was
wondering if there is a way to get rid of it or to better control it.

I feed the fish once a day with frozen food and the corals 2x weekly with a
strontium/zoplex mix (50/50)

It is lit with a blue actinic and high output white light usually 8 hours a
day.

I don't think I can limit the lighting any more than I have.

The corals don't seem to be a vibrant and I wonder if this is all connected
somehow.

Any advice would be appreciated.

Thanx

Todd