Which hair algae do you have? I recently had a explosion of Cladophora an Staghorn at the same time.. I my case it was already in there i knew that and was triggered by doing a lot af water changes to fight of a parasite infection introduced with some infected fish. The algae explosion was the gift a got with it for free in 2 weeks time.
As Jose said, read the tutorials.. You need to get things stable.. That is stable and constant firtilization, co2 is a part of that. Doing a lot of water changes makes your co2 supply in your tank unstable. Plants need a steady supply, once they are used to it, they start to grow. Algae on the other hand like it messy, they are much more addapted to unstable conditions. The plants don't know what to do, don't get a chance to make up their mind and the algae party on that.
You can make things stable with cutting back on everything or other way around as long it is a stable supply so the plants feel at home. This takes a while, can take up to 2 weeks before you see the plants want to explode instead of the algae. Mean while you have to fight the algae manualy, this you can do with sciccors, tweezers, vacuming the substrate and keep the filter clean. Or you can go chemical on them with Liquid carbon or H2O2. At the point where you see your plants growing, you can start to trim even more infected leaves out, while trimming you will find nests of algae.
I used some h2o2 to kill off some places where the algae like to nest. It was also in the moss. Like Fissidens and Pelia. Moss don't realy like h2o2, it shocks them a bit, so you need to be carefull not to kill the moss as well. The pelia hates it and one treat to much and it's killed as well. The fissidens is harder but suffers a major set back and needs time to heal from the damage.
But first find out what hair algae you have and search the forum with that.. You'll find dosens of nice tips.. I did
and it helped me a great deal.
Btw i did fight it off with uping everything.. More and stable Co2, more firts, little bit less light.. Make your plants boom and rock and roll with the tweezers and sciccors..
Don't be afraid to cut, cutting means new growth. That wath plants do, grow back new when you cut them. I know the feeling "All for nothing" But that isnt true, you need to go trough that phase if you have a algae party going..