i have the model 3 proflex and very pleased with it. only thing i wish i did was buy the model 4 so i can have the larger 3rd section. other then that the sump runs silent, well built, you can change the setting for different style sump setups, and it works lol. im very impressed with the proflex sumps but i wouldnt advise anyone to get any model lower then the model 3. if your going to get one look at the measurements in the third section and find a skimmer that you like that will fit in your model. in the middle section the highest setting you can set the water is 11 inches.