Thanks for the input fellas. I might add that my dicision to discontinue feeding is not set in concrete. I may continue feeding if convinced discontinuance could be devastating. The feeding I have been doing has been supplemental to fertilizing; not feeding to satiety. I too have experienced a DO crash resulting from overfertilation. As those who have done this know, it makes one feel totally stupid and incompetant. To waste years of effort in one moment of carelessness is a real drainer. However, I learned a valuable lesson not to be soon forgotten. My own rules of fertilization (some of which are well documented) are as follows:

1. Never fertilize by calendar.
2. Never fertilize by generally recommended amounts per acre of a particular fertilizer blend. Every pond is a law onto itself.
3. Tread carefully if using granular blends (the old type). Personally, I will never use granular blended fertilizer again if I can avoid it. I was using super phosphate when my DO crash occurred. I am not blaming the fertilizer, only myself. I just believe fertilization becomes trickier when using granular due to delayed reaction and desimination times and maybe other factors.
4. In the spring, begin to fertilize by threshold water temperature. I personally begin to fertilize only when the water temperature has generally stabilized at around 70 degrees. This is usually sometime in early April where I live. I think there is a real danger when fertilizing during periods of increasing water temperatures in the spring. My crash ocurred in early May. It seems to me that planctonic response to fertilization is more rapid and total the warmer the water gets. The scenario seems to be this. No response is seen to fertilizer. Impatience sets in. More is added. Water continues to warm. The color explosion occurs as critical mass (so to speak) is reached. Darker by the day. Gulping fish. Dead fish. Total recrimination. Kick the dog.
5. Add fertilizer in increments. You can always add more later. Be patient. Impatience is a real killer, to fish that is. A point of no return has been reached once the fertilizer has been added.
6. Do not willfully go below visibility of 24 inches. I know 18 inches may be ideal however I would rather err on the high side. I may reach 18 inches but not on purpose. Trust me, if visibility reaches 12 inches or below, things get tense.
7. Do not attempt to correct planctonic explosion by addition of algicides. I tried this. For me, it only resulted in a faster crash. In hindsight, I believe I may have survived my situation if I had not tried a partial planctonic kill with Cutrine. I believe Greg Grimes stated that he had guided a customer through a sechi reading of less than 6 inches. I will never again attempt the chemical remedy.
8. Discontinue fertilizing during July and August. These months of tepid water, thermoclines and stratification to me are not conducive to fertilization. The risk is too high. I'll live with visibilities of 36 inches.
9. Begin again to fertilize in September when days shorten and temperatures begin to fall.
10. Discontinue fertilizating around mid October.
11. Never fertilize based on previous years schedule. Each year and season is a law onto itself. Rainfall changes, temperature changes, watershed area changes, alkalinity changes, etc.
12. Be flexible and adaptable in your thinking. Only fools have closed minds. Always be willing to change when circumstances and respected advice warrant.

By the way, has anyone ever seen a report or study detailing alkalinity/fertilizer/temperature relationship in ponds relating to bloom? I haven't. It seems to me there has to be a predictable relationship between total alkalinity, fertilizer (maybe only phosphorus), and temperature that could be helpful to those of us who fertilize to achieve a desired bloom.

Please take exceptions to my rules. They are merely my own thoughts based on my limited experiences in my area. I may be totally off base with some of my personal rules and certainly am not recommending them to anyone.

F.A. Walker