Hey all, I built my first pond around this time last year. You all very helpful and it turned out great. I have only one ongoing problem. I live In Dallas, TX and it is extremly hot here. I am fighting a never ending battle with algae and green water during the summer. My pond is approx 5,000 gallons. I have 2 - 3,000 gallon per hour pumps feeding into 3,000 gallon per hour filters and through 2 waterfalls that also does a little filtering. The only thing I can do is massive water changes to keep the water clear but after about 4 - 5 days, algae is everywhere. I have tried draining it completly, cleaning it and filling it back up. I use the microlift PL bacteria. I do have crawfish in the pond as well as koi, goldfish, blue gill, bass and catfish. alot of the algaecidies say I cannot use them with crawfish. Before I had crawfish, I tried using one but it killed all my fish. Trying to stay away from any kind of chemicals. I also use the barley and peat extract and have a uv bulb too. I think i have tried to cover everything. Does anyone have any other idea what I can do to hold back the algae? I have even put 4 umbrellas around the pond to try and knock out the sun light. I have about 10 plants in the bog. I dont think I have left anything out. Any ideas besides the massive water changes? thanks!