Bob,

This is an interesting idea. I have a similar set up on my pond as Coach does. My standpipe is 8" diameter. I have a very high flow rate, especially this time of year. I calculate it to be about 250G/min at the present. I see the concept and it makes sense. I am concerned that increasing the height of the standby by 6" may be too much. I presume if the diameter of the sleeve pipe is not great enough to carry the flow, the water will rise over the sleeve, correct. Is there a formula that could be used to find out exactly what size pipe would be needed?