You didn't mention any filtration. That will catch some of the algae that floats to the top. Also, if you don't have one you might want to get one of those fine mesh skimmer nets so you can scoop it out.

You might also want to increase your plant surface coverage to shade the water.

I understand what you are going through. I had the same problem. There are a few factors that need to be known. First, you need 75 percent coverage on the surface of your pond water. Water lilies, hiacynths, any floating plants will do. Now, I had that and I didn't get the results I wanted. I used Algae Fix with the right amound needed. Prior to the Algae Fix, I used a sponglike mop and scraped away the agae I didn't want. I waited about a month or more and added another dose of Algae Fix. That worked. My water is now clear and the string algae is gone. Make sure you dilute the chemicals with your pond water before pouring it in.

It really does take patience. I don't have any, but I've learned it's the best way. Some people don't believe in chemicals, but let nature take it's course. Someone once told me a man made pond is not natural, but more of an outdoor aquarium. Good luck.

http://www.lakerestoration.com/c-19-floating-and-submerged-weeds.aspx You might want to look at this website. Glenda

Thanks for the info. No, we have no filtration system. I think I will buy the Algae Fix and some floating plants. There are many other ponds around here where I live and we do not see one with our algae problem! There are larger and smaller ponds and they have no floating plants either and are in direct sun all day. Yet, our pond has the problem and these ponds do not. Any idea why?

Arlene... I couldn't help but notice, you said your pond is about 17' x 40' and about 1,500 gallons. In case it comes up in the future regarding actual volumm (ordering chemicals or ?) but an area of water 17' x 40' at 1" depth is 424 gallons of water. An average depth of 18" would equal 7,632 gallons. I expect you have a bit more water there than you would think.

You mentioned you have grass around the pond. If any ferilizer is used for the grass there is a high probability that the fertilizer had made it into the pond. The same ferilizer you want to make the grass grow will REALLY make the algae grow! Not knowing for sure your situation this a just a possibility.

As mentioned above, your best bet is floating plants, hyacinths and lettus are great filter plants that will propagate VERY quickly. Not sure what area you are in but in some areas they are controled because they can progagate TO quickly.
Good luck
JJ

If you are concerned about the plants propagating too quickly, you might also look into a pond dye to help filter out some of the sun rays. Of course dying a pond is a personal preference, but it can be helpful. Also adding pond bacteria regularly meaning every 2-4 weeks can also help with controlling nutrients such as those that may come from fertilzer run-off or fish waste.

Here is a link that might be useful: Blue Pond Dye

Just another thought...do you have a lot of fish in the pond. Could it be that your fish population has grown over the last couple of year to be more than what the pond can withstand. If that is the case you could have high amounts of fish waste that is providing a constant food source for algae.

Here is a link that might be useful: Pond Maintenance Supplies

Thanks for your responses. I am in the mountains of Julian near San Diego.

We do not fertilize the grass, but my partner thinks that our chicken pen has leached into the pond when the rains were huge and the water flowed down into the pond.

We do have a lot of fish, but they are very small and I am not sure they are making all the waste. We are going to get water lilies from a neighbor that have taken over her pond, but first we have to get the current floating mat out and use something to stop the algae from coming back.

I bought AlgaeFix, but have just read on the package that it will kill crustaceans. We have crawfish in the pond that we do not want to kill, so I am back to square one for something to kill the algae. Anyone know of anything else?

If you are looking for another algaecide, I would suggest GreenClean. It is basically an oxidizer and kills the algae on contact. To my knowledge it has no adverse effect on anything but algae or similar single cell organisms. Use GreenClean and with regular follow up doses of pond bacteria and you should see some benefit,

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

Algae Fix will indeed kill your crayfish and it can kill fish, frogs and plants. I've read many a post by people who have done so.

There isn't anything chemical that will kill algae but leave everything else alone.

You need plants, you need to make sure the chicken pen can't run off into the pond (major nutrients there) and you need patience.

Draining the pond will only start the cycle over again.

Using a black water tint such as the one made by Microbe Lift will also help and doesn't look as fake as bright blue does. I use it in my still greenhouse pond and it works very well.