Here's a couple of layouts we put together for a few clients.
The Kelsay job was to add 25% of the 20% of surface area of the 6.5 acre pond in artificial habitat. The remaining 75% of the suggested 20% was installed with plants, boulders, rock/rubble and large wood. The goal was to add just over 1.3 acres of habitat, or 20% of the surface area as Bob suggests.
The smaller one acre pond in Texas, wanted all artificial habitat, with no weeds or aquatic plants. Note the travel paths from shallow to deep. It is based on 25% of the surface area in habitat.
