Okay okay okay,
before we jump to conclusions, we need to truely find out what algae it is and why it is there. UV sterilizers do not kill attached algae. If anything, they may help to slow down a spread. The algae-eating fish option is good, but they all have their favorite food. To be honest, it does not sound like you have hair algae. Hair algae forms long "hairy" threads (several inches long), is bright green. The easiest way to remove it is rolling it around a wooden stick and pulling it off. Hair algae per se are indicators of very good water quality, and you can only fight them mechanically or with fish. Other algae are indicators of excess nutrients. What are our nitrate and phosphte levels? Pics of the algae?
HarleyK