not sure on hot water, but I know around 70F is where you will get optimum output according the the instructions. I have a typhoon III as well. I run just cold water through it. I still get 50+ gallons a day out of it.
O.K.. Well. Guess that settles it. I was using the hot water spout that is supposed to go to my washing machine. I never wash anything in hot water so I thought I'd use it for my RO water.
Well that sucks. It was so convenient. Now the cold water I'll be using is probably around 45 degrees. Oh well. Thanks for the input everyone