I have the standard Aqua C on a 75 (it was originally purchased for a 55). I also have a CPR backpack. Originally the Aqua C was used with a surface skimmer and did a great job. Since I've added a sump, it was moved into the sump and the CPR is now used for surface skimming. Mine has the Maxijet upgrade and it has done a great job in both surface and sump skimming.