I still think you should test your phosphate levels, Hair algae is a pain in the butt to get rid off.
Even if you emptied your whole tank and scrubbed it clean, there is no curtainty that you would get rid of it. just one pour left in the tank and it would be back. I would remove what ever you have with it on.
I tried to get rid of it for twelve months, i tried every algae remover on the market with no joy. In the end i shut the tank down, cleaned it out and started again. I am saying about phosphate because hairy algae loves it. Hopefully the lower the phosphate the slower it grows. But even with no phosphate it will still grow.