| I would expect that a 9000 gal pond would need two bottom drains depending on layout. What were you going to put into the first Wave 36 for mechanical filtration. A microscreen or static prefilter? The second Wave 36 with Japanese mat will do mechanical along with a lot of bio. You can't prevent that much surface area from doing bio so I'm not sure of the question. I personally would fill the Wave 36 with "bactitwist" instead of the matting because it does a much better job and is much easier to clean. If your Ultima 10,000 is a bead filter it will do plenty of mechanical and should be run off of the skimmer or mid circuits and you could aerate the second Wave 36 letting it do lots more bio but no mechanical. |