A couple of questions about the algae.
Would you describe it as "stringy" or "snotty?"
Does it appear to be gone, first thing in the morning, after lights have been off all night, and then appear to grow quickly and return throughout the day, after lights have been on for awhile?
If you can answer "YES" to both of these, chances are it's Dinoflagellates. If so, they can be quite a pain to get rid of. There's 2 commonly used methods, that are both somewhat successful.
#1. Turn your lights out and leave them out for about 4 days. People are hesitant to do this if they have SPS, Clams, etc, however, they'll be just fine. After day 4, you can turn your lights back on, but only for a couple of hours the first day, a couple more the next day, etc. until you're back to your full light schedule.
#2. Unfortunately, technique #1 usually works temporarily, but it usually comes back. So, the second method, which seems to be a lil' more successful, but is more difficult, is to raise your pH above 8.5 and KEEP it there, for a period of at least 2 weeks. Keeping it there is the problem. It usually requires dosing Baking Soda, several times every day.
I've been lucky with technique #1, but I had to use this technique two times in a row. After the second time, the nastiness didn't come back.
