Yes, unless you have a very large adult female, you can keep two adults in one divided T8 comfortably. If you have a chillier house (like I do) you might need a RHP and a UTH, as the RHP won't make a hot spot, it'll just raise your ambients. If your house is warm, just the UTH. Also, as UTH is short for 'Under Tank Heater' anything that goes under the enclosure to produce heat is considered a UTH, not just the mats or the heat tape.