Nano Tank Refugium Lights?

I'd like to make the HOB filter on my 10g into a very small refugium, basically just adding some chaeto to the area where filter media would normally go. I'm wondering if anyone else has done this, and if so, what are you using for a light source? I have a stock hood on my tank, and will for at least the next few months, so can't rely on the main tank lights to also light the HOB filter. It would be great to find a very small clip on LED that I could add to the HOB filter, but I haven't come across one yet - ideas?

Thanks!!

Here is the HOB Refugium I made by modifying a hang on tank breeder tank. It is a half gallon total. The light we got off of Amazon.com. It was just a clip on refugium light. Here is the link:

[ame="http://www.amazon.com/CL26BK-Aquarium-Cliplight-including-Moonlight/dp/B003GVOF8I/ref=sr_1_3?ie=UTF8&qid=1333320680&sr=8-3"]Refugium Light[/ame]

It may be a little big for your filter though depending on what size it is.
[ame="http://www.amazon.com/CL26BK-Aquarium-Cliplight-including-Moonlight/dp/B003GVOF8I/ref=sr_1_3?ie=UTF8&qid=1333320680&sr=8-3"][/ame]

It your light a dimmable LED moonlight please?