If your LFS
is anything like mine they keep the store very warm so they wouldn't need a heater. I know Carey has said before that her cube runs warm so she doesn't use one either
, however, if you are in a cooler area or a cooler house, for example, I need heaters for the winter months, then a heater may be needed. I just added my "seasonal" heater to the cube as the nights are getting down into the 40s and I keep the house at about 68. Obviously you need to look at your temps and how they run.
Like Carey, I have the media basket in my second chamber that holds floss on top just to catch anything larger, then Purigen, then a combination (separate bags) of de-nitrator and chemi-pure.