It sounds a bit like green dust algae to me. GDA at this stage are free swimming. Clearing up the free swimming zoospores at this stage is very difficult, so here is your best plan of attack, if you are willing to see it through.
The algae should be allowed to complete its life cycle on the glass, which means that you will have to put up with glass that you will not be able to see through for three weeks or so.
As the algae turns in to its adult form a green like jelly coats the inside of the glass. Resist the temptation to clear it off, as it will soon start to fall off and recede of its own accord. I have tried this on all my new tanks that start with GDA and it works. I have tanks that have not required the glass to be wiped for months. As long as you understand the principles of what causes algae you shouldn`t see it again.
The hardest part is ignoring the horrible green, jelly-like goo on the glass for all that time. The reward is worth it, however.
P.S. I hope I have got the type of algae right. It isn`t easy to ID without a picture.
Dave.