Hi Bender sounds like you are working on a great setup. I noticed that at the end of the posting you stated "I am planning on putting some gravel on the bottom. Gravel is supposed to increase the surface area available for the bacteria to grow and help the nitrification process." Keep in mind that this principle only works with an under gravel filter that supplies oxygen to the substrate. Beneficial bacteria must have a steady running flow of oxygen to break down the toxics...you will have aeration flowing if read correctly, however the gravel itself will not function as a filter unless you are pulling water through it. Let us know how your pond works out.
