I am going to add a sand and gravel filter to my pond to help clear it more then my 2 bogs will. Was going to add a sand and gravel filter filter and return to the pond. I was wondering if a 2" return line and a 2" flush drain is big enough. I know the original build post I found calls for 3" but I dont plan to runn 2000 gpm, maybe 1000 at max as I still want most of the water to the 2 bogs. Biggest concern is will the 2" flush be enough.