The use of pond netting to repel fish-eating predators such as herons, cranes, etc. and to keep pond free of leaves and debris is common. This brand of Premium Ponds Net is a high quality knit black mesh netting with 1/4" spaces which is available in many sizes from 10' x 10' to 20' x 25'. Please note that sizes are after net is stretched tight over the pond. Pre stretches sizes may be a couple inches less than quoted.
This netting has a sturdy border and with the use of stakes and or bungees (not included) can be drawn tuant to keep leaves and debree from sitting in the water rotting. It is also possible to use a large beach ball or other floating object to create a tenting affect to further aid leaves blowing off of the cover instead of collecting on the cover.
See pictures for a demonstration of how it can be used: Note that closeup is net type, the other picture is only to illustrate the use of stakes to tighten.
