Pond Boss Forums AQUATIC VEGETATION Identifying plants Cutrine.....Help!

Steve -- There is only one type of grass carp that will be available in PA; the white amur, aka grass carp and scientific name of Ctenopharyngodon idella of the triploid variety ( three sets of chromosomes instead of the usual two sets).

Tests of feeding preferences of grass carp in USA and New Zealand showed Nitella was a preferred food. So not very many will be needed to get your "weed problem" under control. Beware of stocking too many and then they will run out of food and then they tend to start rooting in the bottom for invertebrates to eat. Rooting will result in muddy or more cloudy water that you don't want. Once in the pond g.carp are hard to remove. It is much easier to have to add a couple more than trying to get some out. I think 10 to 12 fish per acre will completely eliminate after 2 yrs an infestation of Nitella that covers 60% of the pond bottom.

Best used; you should stock enough g.carp to eat about 30% to 50% of the Nitella. You then should remove about 20%-25% of Nitella each year with a Lake Rake or similar speciality tool and let 25% remain in the pond for fish cover and to compete against other forms of more noxious algae like the filamentous types/species.