Pond Boss Forums GENERAL QUESTIONS Help New Pond Owner Needs Advice

Mark - Greg points out a big disadvantage to stocking 10 grass carp per ac. when he says they completely cleaned out coontail in 6 acres. In my opinion one wants some vegetation in the pond to provide refuge areas which are essential for development of small & medium fish and important competition w/ filamentous algae for nutrients. Aquatic plants (depending on bed size) also provide growing places for millions of zooplankton and aquatic insect larvae which feed small fish. Weeds or aquatic vegetation acts like artificial structure ONLY BETTER. Of course this 'having weeds' philosophy contradicts the pond fertilization philosophy. Pondmeisters have to decide on one style or the other and manage toward that direction. The 'having weeds' philosophy is more commonly practiced & works? better in the Northern states.

Too much aquatic vegetation is usually bad except in wetlands; ideally for a balanced predator pery community the water body should have 20% to 30% coverage. From 35%- 40% it starts getting to much/thick and beyond 40% coverage the small fish have too much cover and the predators have a hard time finding and preying on small fish. Ideal percentage of weed coverage is also dependant on the type of weeds. Some weed types or species are better suited to predator foraging than others.

Anyway - as Greg points out, too many grass carp can create another problem, often just as big as the overabundance of weeds. Once in teh pond they are very hard to remove, instinct makes them want to survive and stay put! In my experience and opinion, when using grass carp start by stocking lower numbers, allow them to work a couple yrs. See what they can do and then if necessary add a few more/ac depending on weed conditions. If stocked appropriately, it takes the fish abt 2 yrs to make a noticable change in the weed community. As the fish get old (6-8yrs) or about every 5-7yrs about 30% to 80% (depending on conditions) of the original stocked number should be restocked to compensate for old fish which do not eat as much vegetation as younger fish. REMEMBER - you want to leave 10% to 30% weed growth intact and thriving to enhance the fishery assuming a good fishery is the main goal..