Infrared heat lamps can be used 24/7 without any issues. If the 50 watt bulb can create a 90 degree hot side and an 80 degree cool side in the 10 gallon tank a UTH isn't necessary.
I would recommend that you get a 75 watt infrared heat bulb and a lamp dimmer that way you can dial in the right heat output.
http://www.petsmart.com/product/inde...uctId=11147193
http://www.homedepot.com/buy/lutron-...l#.UHzcO7Q2KRk