Hello, I have one of those small formed plastic ponds with a few koi and goldfish. I also have a formed 3 tier waterfall running into it. I didn't care for the unnatural look of the black plastic waterfall so I llined the bottom of each tier with rocks. About a week later the rocks and the sides of it were bright green with fuzzy algae. But my pond itself doesn't have any visible algae. I have read that algae is good but it is very unsightly in my waterfall. I have not used any algae removing chemicals in my pond, but I do have two plecostomus in it that a pet store recommended. Any suggestions how I could make my waterfall look a little more natural, a little less green and keep my fish happy? Thanks, Brandon

Have you read over my algae page at http://www.fishpondinfo.com/algae2.htm
It sounds like some attached algae or hair algae is growing in the falls. It is helping to filter the water for you so it's not all bad. You can plant some plants in the falls like watercress (see http://www.fishpondinfo.com/plant3.htm) to compete with the algae and filter the water. Also, if you block some light to the falls, less algae will grow. Adding plants helps to do that but other things can create shade as well.

How big is the actual pond? Is it big enough for koi? The plecos can't eat the algae in the falls because I assume that they can't get there. Keep an eye on the plecos in case they decide to suck on the goldfish or koi.

I read your pages on algae and plants and found the information very helpful. You are correct about the plecostomus not having acces to the waterfall. My pond is very small, about 125 gallons. I plan to get or make a bigger one next year. My koi are only about 4-5 inches now. When I bought this pond I thought that it would be plenty big enough and didn't intend on getting koi. The more I read about koi and ponds, and the closer I got to having my pond finished this spring, I just had to get some. I will try some of your suggestions and let you know how it works out.