I guess my concern would be if you had a film covering the entire pond. I would think that could inhibit the pond's ability to exchange gases with the atmosphere.

Edit: Spraying an oil film on BOWs is/was a common practice of controlling mosquitos by preventing O2 from entering the water and suffocating the larvae.

Last edited by Bill D.; 03/19/15 09:16 PM. Reason: Clarification

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