Wow, that's quite a bloom! A UV sterilizer will clear it up as already stated. But the real question is what caused it? I'm not a fan of the sterilizer a personally but I know many swear by them. Since you've already ordered it and the bloom is pretty severe, I'd say to ahead and use it, but you should try to isolate the cause.
What are your water parameters, and what is your lighting schedule! How old are the bulbs (if applicable)? I think the goal here should be to not need the UV unit again once this is cleared up.