Owner's Top Floats are an excellent choice for fishing still water. Their shape makes them very sensitive to the most subtle bite, which is wanted while fishing lakes or ponds. The shape also makes them a much better choice than the Nakazima Ball Floats or the Owner Acorn Floats. Three #6 shot will be sufficient so that only the bristle of the float is above the surface (depending on the weight of your hook and bait). Rigged that way, a fish will feel almost no resistance when it takes your bait or fly.
These floats in are the 100mm size, not the 85mm size shown in the image.