Been trying to get this under control as we have taken over the pond maintenence in our neighborhood of a 1/2 acre spring fed pond. I thought this was chara but getting little to no effect from cutrine plus. It does seem to brown when there is muddy water but soon recovers when it clears. It appeared a couple weeks after all the FA was gone. We are running a dual head aerator and two fountains and this grows anywhere there is shallow water and is anchored well in the silt/muck. I can't smell anything when I crush it. I thought it was Chara but think it may be a pond weed. Any help is much appreciated. Thanks!