My pond is shaped like the letter P its 21 feet long 18feet at the widest and the smaller size is 8 feet wide buy 10 feet long. It slopes from 3 feet to 5 feet. As far as filtration goes I run a Tagelus TA60, Laguna Pressure-Flo 3200, a Tetra Clear Choice PF-3, and a coral life 36 watt uv. My fish range any where for 6" to 30"