I haven't looked at Aloft lately, but you're memory usage is going to gradually go up regardless of what you do depending on how you recycle tables, you're going to be storing more data on mobs etc. If you're not using disembedded libraries, it could always be Ace2 that is contributing to it as well. You could always try luac -l <file> and look for (or grep) SETGLOBAL to see if you are leaking any globals.
Is it about 187 KB/hour or is it 300 KB one hour, 100 KB the next etc? If it's consistently in the range of 187, look at anything you do on a timer. It's possible you're creating a table or function on a timer.
OptionHouse isn't very good for actual profiling, you could also try
Addon Profiler and see if you are creating 187 KB of static memory or 187 KB of garbage which would narrow it down a bit more.