One point of many good ones that Ted made is the water temperature difference between the top and bottom of the pond. If your temperature is more than 5 or 6 degrees F difference between top & bottom then that indicates DO is likely low, will soon be low, or non-existant at the bottom where the temp was measured. The greater the temp difference than 6 the more likely DO is abscent. Remember tests for DO verify this feature, but the temperature difference which is a lot simpler and cheaper to measure is a very good indication of what is probably happening with dissolved oxygen in your pond. Exceptions occur but these usually do not occur in regular 'fish' ponds/lakes. Your pond is probably not unique in this regard. NOTE: this applies to mid summer conditions and not during winter or cold seasons.
Last edited by Bill Cody; 02/16/12 10:43 AM.
