Currently I don't have a nano tank but there may be one in the future. Some time ago while researching skimmers I came across a product from Japan that is made of glass.
http://mame-design.shop-pro.jp/?pid=6515458
There are some reviews on the reefbuilders site. There was(is) also an outfit called Gnome that produced something similar, but some folks got scammed & it seems the business never really got off the ground.
Just throwing this out there for anyone that may be interested in a non-DIY skimmer for their nano that is a little work of art & will look good, not use up a lot of space. And it may help your DIY effort by giving you some ideas.