Scoop out with a net. I think if you were to add some sort of pump with filter to keep the water moving that would also help. If there are no fish I would go with the frequent water changes too. There are conditioners and pond cleaning products you can buy but for such a small water feature I think just clean it out and stay on top of it.

Thanks for the replies tropicbreezent and plaft.

My pond size is 3 ft dia and 1.5 ft height. A friend got some lotus plants from a nearby lake which i added to reduce the sunlight but the leaves were too big and old (dying) so i trimmed it. The water lettuce (pistia) multiply quite fast. I'm looking out for water lily plants as they have smaller leaves and will look neater and fit better in the small pond.

The pot trays I added are acting as temporary sun blockers till i get the lily plants and the pistia increase. i think almost 70% of surface is covered. Let me see how visibility improves. Thanks and I hope to update with improvement.

by the way how do i upload a video from my pc ??

I had surprisingly good luck with barley straw. I got a small bale on ebay that was supposed to be enough for a 2000 gallon pond and put it in my 4000 gallon pond. The water cleared up remarkably!

Good luck with your pond. Sorry can't help with the video uploads as I have not done it yet. But it looks like if you want to you need to upload to YouTube and then upload from there the here??? No sure.

Finally it worked! Blocking the sunlight helped clear the algae. Within a week of covering about 60% of the surface, the water was clear. So now I keep it covered 30% with the pot plates and the plants cover some more 10%. The algae never reappeared. The oncoming cooler season also could have contributed. A clear pond is pleasant to watch indeed!

Algae shows up when you have and excess of nutrients and sunlight with the water and a lack of other plants to take up the sun and nutrients. There are very reputable water garden companies like pondmegastore.com with lots of water iris, small water lilies, and marginal bog plants that are perfect for a container garden like this.

Be sure if there are falling debris to remove them if possible before they decay, same if there are old or aging vegetation no longer growing in the pond.

The systems should be a balanced ecosystem, there is really never a need for chemicals and if you do get a temporary bloom of algae no need to panic it is unsightly but is not hurting anything.

Fish pond- you mean there's fish in there? Well that explains it - as others have said, excess algae is a result of excess nutrients. If fish, you should be doing frequent water changes anyway... for the health of the fish. Really, not so difficult esp. with such a small container- just siphon off from the bottom to get out the sludgy stuff.