I'm an officer with a local Lake Association. Our Impoundment (reservoir) has a long history of fish kills. At 6800+ acres and over 18 miles long it is impractical to aerate multiple areas so in 1981 a large system was installed to provide a refuge during periods of low DO. It was located in an area that was both convenient as well as being was a narrow passage that could easily be cobered. The area of the open water field is approx. 40 acres. Yes it is huge. There are 2 blowers each with a 40HP motor and a 775 CFM capable Cyclo blower. The picture below shows an aerial photo of the field in operation.
The system stands idle until February when it is started up based on demand. During the months of December and January a small system is operated to maintain an area of open water where the tubes enter. This system is what I am looking to address.
The standby aerator is a large tank piston compressor set to deliver air via an orifice. The cost of operation is on the order of $10 a day. In a typical year it will run around 60 days so that is $600 to do the job of a typical pond aerator. The motor is in need of repair which is understandable as it cycles far too often running 1.5 minutes every 5 minutes. At the very least the cycle rate needs to be addressed.
What I'm looking to propose is that this existing equipment be kept as backup, but look to add something that runs on the order of $30 a month versus $300. It needs to run reliably 24-7 approx. 1500hrs straight and truth be told does not need a diffuser. A simple orificed hole has sufficed for all these years and requires no maintenance.
I'm hoping some of our aeration experts can chime in here with suggestions.
For a little perspective from the edge of the visible ice area to the aeration field is 5.6 miles:
