no u wouldn't need a proteen skimmer but nost would sugest u did i have a 10 gallon nano with out a skimmer but i have built in a algale scrubber here is the link to the alge scrubber thread on this site
Mega Powerful Nitrate and Phosphate Remover - DIY! i really sugest u think about these thay are the best thing that ever hapend to my aquariums
oh and if u look at the first couple of pages and find there all for biger tanks because i know that there is stuff on nano algae scrubbers have ing started on them and thats how i got in to reef tanks if i didn't use a scrubber it would have bean to expencave and unrelible being a small tank but its more the unreliable part (everything is allway changing so u allways have to do tests and stuff) and havein to do lots of water changes