Patent ID: 7267766

Claim:
A method for aerating a particular stratum in a multi-stratum liquid body, wherein the multi-stratum liquid body comprises a lower anaerobic stratum comprising anaerobic microbes, an upper aerobic stratum comprising aerobic microbes, and an intermediate facultative stratum comprising facultative microbes, the method comprising: providing a depth-adjustable, fine bubble, surface layer aeration unit comprising: a body comprising at least one hollow internal structure; an air inlet communicating with the at least one hollow internal structure, whereby air from an external air source may be introduced into the at least one hollow internal structure; at least one fine bubble aerator communicating with the at least one hollow internal structure, whereby air from the at least one hollow internal structure may be released through the at least one fine bubble aerator into an adjacent fluid; and at least one weight pod attached to the body, wherein the at least one weight pod comprises structure for adjusting the weight of the at least one weight pod, whereby the buoyancy of the aeration unit may be adjusted so as to permit the at least one fine bubble aerator to be positioned at a desired depth in a fluid body; connecting an air source to the air inlet, and positioning the aeration unit in the multi-stratum liquid body; adjusting the weight of the at least one weight pod, so as to position the at least one fine bubble aerator entirely within, but only within, the upper aerobic stratum of the multi-stratum liquid body; and passing air into the air inlet and out of the at least one fine bubble aerator so as to aerate the upper aerobic stratum without aerating the lower anaerobic stratum and the intermediate facultative stratum.