My pond is now 4 1/2 months old, the dark algea that was on the rocks on the waterfall seems to be "cleaning up", I have taro, water hyacinths, lily, cork screw, a grass and a couple other plants I cant think of their names inside the water. They all seem to be doing really well, yet the black taro in the water (in lava rock) is real light green and growing like a weed. I have 5 goldfish bout 5" (who eat well) who seem to thrive in this ponds water and my water is always crystal clear. Guess I'll just live with a few light colored plants and higher ph lol.