Only a centigrade drop? With my other pacman I've been maintaining a 27-28C during the day and 23-24c at night. Do albino like staying warmer at night? I got a 50W red bulb here for him. He chirps sometimes :-)
A slight drop is recommended. It can be as low as 76°F (24.4°C) or as high as 78°F (25.5°C) at night. It has nothing to do with the frog being albino just a recommendation. You could use the method you are already using.