I don't have a 75 but I'll be setting up a 55 austrailian rainbow tank and I'll be running a 2217 and a power head. If I needed more I'd wait for a sale and get another eheim. I just picked up a 2213 for $75 and I've seen the 2217 as low as $105 on a daily deal at marine depot. You have more than enough room for both of the out flows. Right now I have both a 2215 and that 2217 on a 46 bow and it's more than enough flow for the tank. sometimes I have debris floating but that is my usual indication of water change time and I also have a pleco and she likes to stir everything up.