I have another question I realized I don't know the answer to. I have a big waterfall filter with lots of spring/tape style filter media and two matala pads inside. I'm still waiting for the water to clear up. We have had some COLD nights but I think Spring is going to be here to stay now. We're going back up into more seasonal high 80s for the highs and mid-60s for the lows. Here is the question: do the helpful bacteria that consume nitrogen/waste need the warmer temps to thrive? If so, that would make sense as to why my water is green right now. As I mentioned before, there's not much plant debris in the water and the pond is not overstocked with fish. (I'm still trying to find encouraging thoughts to keep me patient with this yucky water.)