sidewinder770
New member
If you plan on using a dart or anything that will give more than 1800gph I'd definately suggest the 2" input and 1.5" outputs. Even then the backpressure from the dart causes the OM to "click" sometimes if you use a version 1 drum. I have a version 1 and modified it to stop the clicking but would suggest a version 2 if using a pump like a dart. I just went from the dart1.5" output directly to a 2" adapter. You can always reduce the input if you want with a 2" but you can't go bigger if you get the 1.5" and if I remember correctly you can't get the 1.5" OM input with a 1.5" output but maybe they changed that since I got one. A 1" output would be really bad with the kind of flow big tanks need as it restricts flow it to much.