I need to lower my temp about 4-5 degrees in a 120g FOWLR. The Coralife 1/4 hp is rated up to 125g, but I've read that oversizing a chiller is recommended so that it works less, hence lasts longer. My issue is the $200-$300 difference in price between the 1/4 hp and the 1/2 hp (the 1/2 hp is rated for up to 250g). Any advice on this? Feel free to recommend other chiller brands too.