Fan direction for Nano??

[frozn]

Hi, I am adding 2 fans to the front flap of my 24g Nano Cube. I was wondering which direction I should face them.
A. Both In
B. Both Out
C. 1 In, 1 Out

 

[zanoshanox]

B

 

[frozn]

More help plz!

 

[teen]

one in and one out. you want fresh cool air going in, and the hot moist air going out.