I'm not familiar with Grass Carp, so I googled it and found this interesting site along with a lot of other sites. Do you have a permit for them? What are you trying to control with them in your Lotus Pond. I don't see a lot of stuff they control? Glenda

myfwc.com/fishing/permits/carp.html

try a local fish hatchery. Call your county extention agent for the location. Is this a liner pond? You do realize that grass carp are not algae eaters....right?

Grass carp as stated previously do not eat suspended algae or pond scum. They are used to control aquatic weeds or sometimes the plants that we would be introducing for algae control.Fish hatcheries is where you would find them if they are legal in your state.

FM4

Algae usually means things are not in balance. Too much sun, not enough plant cover etc...I would try to go that route rather than thinking about an exotic fish species that may become a problem in itself. You did not give enough info about the size of your Lotus pond, does it have fish, any other plants??? More info might bring more helpful responses.
Good Luck
Dianne

My state does not require a permit but everywhere I go to doesn't carry them. I have a pond that is about an acre and I have egyptian lotus and american lotus that takes up about half of it and there are some reg. water lilies to. But, there are weeds and floating algae growing out of control. I keep netting it all out and its full again in the next couple of days. I'm afraid it will start affect the fish. I have no liner. What other plants could I plant to choke out the weeds and algae?

There are pond-safe herbicides made for natural ponds, but be aware that anything you put in there to kill weeds will also kill your lotus plants. They make algae killers, but the rapid die off of algae will eat up the oxygen levels in the pond, possibly killing your fish. You really need to talk to your county extension office for advise. It's nearly impossible to control pond algae, it feeds on the organics that are in all dirt ponds. There are no plants that will choke out floating aquatic weeds and algae.

If there was a fish out there that ate algae and was problem free.....every pond store would carry them and all of us would know about them.

The algae gets going before the bacteria and plants do in the spring. So if you tackle newly forming algae now, it should clear up in a month or so.

I would use barley in there as the best natural way to kill new algae for your size pond. Put 1/4-1/2 a bale of it in now and another dose in about 3. Weight it down with some rocks as it will float for a day or two.

It will break down in to a mild hydrogen peroxide compound that kills new algae cells and is pretty safe for the rest of the plants.

The link below is detailed about how much to use and where to use it.

Here is a link that might be useful: Barley and Ponds Link

Actually, there is a fish out there that only eats algae. Tilapia are algae eaters! So put some in there (wait until the water is 70° because they are tropical) and let them eat algae all summer. then in the fall when the water starts cooling off, harvest them and have a fish fry. Tilapia is wonderful tasting fish!

Have you looked into adding any aeration? Aeration can pay big dividends in controlling algae, especially in an earthen bottom pond. There are also other things like dyes to help filter sunlight where your other aquatic plants are not. Our company helps a lot of people with large ponds control algae and w/out hazardous chemicals and one product talk to people about is GreenClean Pro as it is safe for all types of aquatic life. Combine that and some beneficial bacteria and you have a solid 1-2 punch for controlling the algae. As someone mentioned earlier, oxygen depletion can result if you kill too much algae too fast, however you also must realize if you kill algae and it is left to naturally decompose, it will simnly fuel another round of algae unless it is removed or broken down by bacteria.

Here is a link that might be useful: Pond Algae Control