Ponderings from Cool Ponds

String Algae Treatment and Prevention String algae can be a real pest.  We often see it start to thrive in late winter/early spring before aquatic plants begin to emerge or when it really starts to heat up in the summer.  We refer to string algae as any type of "hairy" algae that's growing in your pond and becoming unsightly.  Sometimes it might grow on the bottom of your pond then dislodge and float to the pond surface during the day. It's not harmful to your pond or fish, but when left to grow, it becomes a real nuisance very quickly. -- This article is about string algae in PONDS if you have a  PONDFREE or PONDLESS Waterfall, read this article instead. -- As a side note: Don't kill algae in a pond with algaecide . This is very common and you could cause yourself a lot of heartache.  When you use an algaecide it kills algae fast. As the algae is quickly dying, it's pulling oxygen out of the water.  Your fish need that oxygen, especially when it's hot....