Originally Posted by tadpole
Thanks Ric, but friction loss is not what I am referring to, although it may influence the answer.
An example of what I am wanting to be able to determine in future projects:
You have a 1" ID pipe through which is passing water at the rate of 500 gph at a pressure of 30 PSI. You reduce the pipe size to 3/4". What is the new PSI? What is the formula for arriving at this answer?
There are Fountain pumps and there are transfer pump. Fountain Pumps will produce more pressure and less volume. The Manufacture should have pressure and spray height data on their website. Along with nozzles and light kits etc
My main point being, it is the type of pump that is the important factor. Only other thing I can tell you is Trail & Error on the pumps you are now using.