I have been in the pond hobby for 32 years. In the beginning we used to have 14 ponds where we imported, bred and raised quality Koi from Niigata Japan. In some ponds the water was so green we could not see our fish, in other ponds the hair algae was so long that it trapped and killed many young Koi. We started to use upflow filters and before we knew it, the water in green ponds cleared up and the hair algae disappeared in the other. After about a month, the water started to turn green again and the hair algae returned.
We then started to use a new filtering system and from that time I never had any more hair or suspended algae.

28 years later and a cold wet summer here in Ontario Canada, some of my ponds have hair algae and in the others the water is very cloudy, sometimes with a green tinge, sometimes with a brown tinge. Because my filters work so efficiently, I don't have any algae on the sides of the pond which bothers me a little because I know that it helps to filter the water and is a good food for Koi and Goldfish.

For 28 years I've used plastic scrubbies for bio-media but this year I changed to bio-balls, the white ones used for packing items.

We have many trees in our yard but we keep the ponds covered so that the leaves can't get in. Can someone help me figure out why my water is behaving this way. I am concerned that it's the bio-falls maybe not having enough surface area for good bacteria to grow on or maybe it's because of the cool wet summer we've had this year causing the pH to fluctuate. I've always prided myself in the clear quality of my pond water but this year has really stumped me.

Hope someone can give me some ideas so that I can share them with our club Members.

Hugs, Lorraine