Wood- one other thing, i put in 4 pounds of Agua 5 bacteria each spring and this keeps everything you don't want in a pond in check. I hate to spend the money but this spring my pond was looking alittle sorry so i added the stuff again and in a week it looked great. It really helps break down nutrients ect. The Agua 5 has 2 billion colony forming units per gram so it replicates easily and will always work overtime. Once you charge the pond you only need to use 2 lbs the following year. My supplier has pictures of dead ponds (as he calls them), once he added the Agua 5 in large amounts they came back to life as the pictures show. He consults with pay to fish pond owners is Colo and Wyo.
jd
