Hair alage is a water filter, it filters phosphates and impurities out of the water. You can start with RO/DI water but if you are going to feed your tank you will add phosphates to your tank. Add a hang on the back fuge with Chaeto or a phosban reactor to remove unwanted impurities. Sometimes you can just add a ball of Chaeto to your main tank, it usually sits in one place. And the biggest thing is be patient it will take a little while to fix itself.