Hi, it sounds like the problem we had. We got our tank (our first) in December and had been battling the water since January. It was cloudy and had a slight green tint to it (which got more green as time went on). It's not like we'd neglected our tank: we did 10-20% water changes every week and tested the water (which always came out fine). I thought maybe it was the driftwood so I took that out - no change. I thought it might be the coral rock, took that out - no change. Thought it might be the food, stopped using that brand - no change.
We were going to Uncle Al's but they either gave us stuff that didn't produce any results (and may have actually killed two of our fish) OR gave us the old "give it time, it will work itself out" line.
So, after nearly 4 months of wasting our time and money with Uncle Al's, we tried a small pet store nearby. The guy gave us some liquid (for free, no less) that coagulated the algae (it then drops to the bottom and you can vacuum it up), which cleared the water by 60% within 24 hours! But then it started getting a little less clear (not a lot, but we didn't want it to revert) so we went back and he showed us the product he used - it's a water clarifier - you use it every two days until the water is cleared up. Also, he gave us some red liquid that he said was a "concoction he adds to bad water" (his helper said it was iodine) so we added another dose of the clarifier along with the iodine and BAM - crystal clear water the next day. We went on vacation a day later and the whole time I was wondering how our fish were doing - whether the water stayed clear or not. Honestly, I expected to walk in the door and see the thick green water we were battling the last few months BUT the water was still clear! Hoo-ray!
Needless to say, we won't be going back to Uncle Al's - they NEVER suggested anything that actually worked and we just wasted our money with them.
You may want to ask your LFS about the clarifier (and even iodine). Like I said, we tried everything Uncle Al's suggested for 4 long months and got NO results and then what this new LFS suggested did the trick overnight. Amazing. I wish we had switched our LFS four months ago - our fish wouldn't have had to go through months of green water and we would have saved ourselves not only money but headache, frustration and worry.