Is there an ideal size for building a pea gravel bed for BG spawning? We are wrapping up construction on a 25 acre lake and will have several areas in the 3-4' depth range and I would like to build some bedding areas. The plan is the use some 2x4 or 2x6 lumber to make a square or rectangle frame and line the bottom with geotech fabric then spread pea gravel in them. We have lots of space for this but just trying to figure out how big to make these bedding areas. 20'x20'?