Hi, I have only used RO/DI water and had the huge, ugly outbreak of nasty, stringy, brown algae and hair algae. I did not use chemicals or phos sponge or phosban, I rode it out! Took about 2.5 weeks from begging to end. Was going insane and about to try phosban when in the span of 3 nights Fri- Sun this past week it disappeared! Love it, Love the snail Army I have and Love the way my tank looks now. If you want to see what my tank looked like last week search for thead "Going Insane", Who Dey saw it.If you used tap water first I would probably say try the phosban, could cut the time in half. Good luck.