Thanks for the responses. I've read that article many times. One of the article's suggestions was to deny light.
I use only RO water. I replaced the filters about two months ago. I have not checked the TDS on the unit lately.
I do manually remove several cups worth on a weekly basis.
I will be moving to a larger tank in the next two months. I would like to use the live rock I have now in my new tank (because I really like the shapes of the rock) but I don't want to start that tank out with this problem. I thought I could use the time remaining to get rid of the algae.
The picture below gives a little idea of what I am fighting.