To properly size an aerator one has to know the water flow rate or up welling flow (lifting rate) produced by the diffuser. Generally the homemade diffusers are not as efficient as the commercial ones that are specially engineered and designed to produce maximum flow using the least amount of air volume. It is hard to calculate the flow rate of homemade diffusers but one can come close to the flow estimate if one knows all the components. Depth of the diffuser also plays a role in flow volume. Calculating aerator flow is sort of similar as calculating fluid flow rate through a pipe - one has to know all the variables.
The general rule of thumb that I start with for clients is the smaller you make the bubbles and the more bubbles you make the more the flow. Next. Too small of bubbles (pores) from the wrong type of surface material tends to allow the pores to clog more quickly - it depends. Air released from an underwater pore tends to accumulate or collect solids in the pore from dissolved solids such as lime and minerals (iron) in the water. The accumulating solids allow for various types of bacterial and slime growths in the pore dispite air flowing through the pore. I don't know the academic reason this happens but it does.
If one lives in Texas or almost anywhere in the US and the pond is 1 ac or less the water deeper in the summer does not mix naturally deeper than 6-8ft deep. This depends but generally is correct for many sized ponds. All one has to do is measure the temperature of the water at the surface and temperature at 6 ft and 8ft and bottom. Any difference in temperature from surface and deeper greater than 6F indicates the surface water is not mixing to that depth.
Last edited by Bill Cody; 02/10/13 08:42 PM.
