my parents (who i live with still...d'oh!) have a large pond in the garden, which my dad estimates is about 300 gallons at least. fish-wise there are 2 koi (one ~8", one about ~5") and around 20 goldfish/comet/shubumkin hybrids(!) of varying sizes, between 1" and 3.5". oh, and a family of frogs! my parents were wondering if some sort of algae eater would be ok for the pond (the sides are very green, but the water's pretty clear - they run a large filter with a UV lamp), and if so, what type and how big. i said i didn't know but i knew some people who might

I really don't know anything about algae eaters. My cousin has some in her pond but I don't know what kind. I don't mind haveing the green algae on my pond walls. My fish LOVE to eat it. When I put the dogs out in the morning, almost all of the fish are sideways yanking off the algae. You don't know how many times I went running down there in my bare feet and in my pjs thinking that they were all floating. Nope, it was just the fish having thier breakfast!

Hope someone else can answer ya!

A lot of pond people have algae eater in their ponds, just to keep the pond cleaner from algae and other debris. The most common ones are those dark grey/black looking kind, although they really are gonna get big and eat your algae away in no time, and turn on your goldies later on.
I have a few ponds, too, but I prefer the algae carpet on the surface areas instead of a ugly looking pleco in the ponds. Especially with a rather small pond like 300 gl, the pleco might be done with the algae really fast, and then starts chasing after the goldies slime coat. A pleco might be more effective, and less danger to the goldies, in a bigger pond....
But there are a few nice looking plecos around, my favorite being the goldnugget pleco. He is all black with a few yellow dots, but with age and size of the pleco his whole body will be covered in those yellow dots, and he gets a fine yellow edge around his fins. Looks really pretty!

I have a pond approx. 750-800 gallons. I have 3 fist sized brown apple snails and 3 golf ball sized golden apple snails (along with many many pond snails). The snails do a great job at helping the fish eat the algea. My fish love the stuff. There isn't much else you could get for "debris" other than crawfish and I wouldn't recommend them. I have about 6 of them this year and while they do a good job of getting debris they also will bother the fish if they get sick (depending on the size of the crawfish). Some algea is good for your pond. As long as it is the string algea or the other green furry type algea it means that your ecosystem is working.

Good luck.

Where do you live? What is the temperature by you? I live in Illinois and I cant have plecos in my ponds. When we first put in our 250gal pond (which is now a huge one!) We had put a pleco in there and a few dyas later it died The temperature at night was too cold for it. and this was during the summer too.

heheh im paling on makeing a other pond this year because i moved
lol im plain on gettin g 2 kois and putting acouple of goldfihs in