Is better to use 1 size up and that is 1/5hp. I'm using a 1/5hp now for my 3x2x2 and that is about 90Gal. Takes an hour to chill down and rest for about 2hr.
Selling a brand new unused Sicce wave surfer for $50. SMS 81254559.
http://www.sicce.com/prodottiDettaglio_eng.php/prod=wave-surfer/subcat=controller/idsottocat=21/idcat=1/idprodotto=79