Plenty of good advice here. But here's some more: some people (including myself) find the pejorative use of the word "gay" to be extremely offensive, and it really isn't appropriate on a public forum like this.

Find something that will eat it. I.m not sure what's eating it in my tank, but something is. Try Mexican Turbo Snails, and an Abalone.

Run a refugium with macro-algae. Use a 5500K bulb or so to encourage the hair algae to grow in the fuge and not in your tank.

Run 1200K bulbs or higher on your display.

Use GFO! Hair algae needs phosphates to grow.

His tank is going through a cycle....

He set it up not even a month ago so this is normal just let it ride out the cycle then either put a seahare or golden rabbit fish both great for manicuring a tank.

hmm yah i think i will either go with a sea hair or do a water change with tap water again like i use to, i feed frozen food, every other day mysis shrimp and brine, i mix with tank water and pour in, or feed from my hand.

I'm having hair algae for my tank as well.
My tank is also newly setup, and I came back from a 1 week trip finding my light timer was stuck at on.
It looks like a planted tank..
I've bought a sea hare and lawnmower blenny and I am seeing some improvement already after 3 days.

I don't know if I would switch to tap water. That could make it worse. Tap water will still always have much higher nutrients/TDS than RO water. Even if your filters were old or not working properly. The RO unit is not the problem I don't think.

I am still having hair algae problems. I am on RO/DI, phosban reactor, algae pruing, water changes every 2 weeks, hermits and snails.

Next is to add a sea hare.

Carmen: If your sea hare knocked back algae in your 72G in 2 weeks then my unit will be cleaned up in less than a week by a sea hare. I am a little concerned about starving the sea hare before I find a new home for it. The local LFS had a sea hare that was buried in the substrate. Do they eat nori or substrate material when they get hungry?

Oscar,

I did notice my seahare eating my red macroalgae many times (Almost seemed to prefer it at times?!)
But I don't know how long it would continue to eat it???
Mine never did bury into the substrate and I did not see it eat anything else.
See if the LFS will let you "rent" the seahare and return it for partial credit when finished with it. That is what I did and I thought it to be a remarkable program to help preserve their little lives. Neat critters.