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

I have been using Cutrine (granular and liquid) in an effort to control a weed that someone told m ewas Nitella. It does tend to knock back the growth a little but within a month or so I'm back to square one. What do i do? Does aeration help?
What about Reward? Are grass carp worth considering -if so, what kind?

Nitella is a branced algae so cutrine granular should work. I would use it over liquid since it is low growing. I suggest grass carp if you want total conrol.

Any suggestions on what kind of grass carp? I would prefer something that doesn't stir up the bottom too much. How many should I put in a 2 acre pond?

Algae is something that will need maintenance to keep under control in most situations. I would continue to use the granular for best control. You may also want to use Aqua Shade to darken the water for longer control between treatments. It is an EPS registered algaecide/herbicide that really can help this situation.

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.

One more question: A friend cautioned me about these fish, as he had heard that their excrement is high in nitrogen which encourages further weed growth. Is their any difference between that and the weeds that are killed by chemicals and then decompose on the bottom?

Steve, I would just use the cutrine granular to knock the nitella/chara back in priority areas (like a beach or shoreline) and leave the rest alone if you can possibly live with it. Regrowth in one month is typical. Aquatic plant control is often like mowing your lawn, you need to repeat after the plants regrow. IMO the low-meadow growth it produces will be preferable to the plant material which replaces it with either grass carp or a pond-wide pesticide application. That is unless your pond is so shallow the nitella approches the surface throughout. In that case you have more of a depth problem than a plant problem. I'm kinda skeptical about being able to manage your grass carp grazing with enough precision to actually pick the percentage of nitella that is removed. If you handle the problem yourself, it will be more work, but you will maintain control over the ponds plant community.