External Pump Info.

[Okguy]

I have a PS2 for my livingroom tank and it is dead silent. According to their website it does increase tank temperature 3-4 degrees but I've only noticed a 1 degree increase. I'm sure it would be even less in a 135 gallon.

I agree with Michika that you might want to look at a pressure rated pump (the PS2 & 3 are but the PS1 & 4 are not) so you can have better control over return flow.