I'm not sure if this is something you can give an answer to, but I don't know in which category this belongs.
What is the difference between parallel piping supply and series piping supply. I cannot paste a drawing of the piping that I did, but I will try to explain it. However, I split 1"pipe in 3/4'' and 1'' pipe. Length is about 50 meters. I connected the pipes in a manifold which supply building 3/4'' pipe, and the pool 1-1/4''. I had water in the building, but almost no water in the pool. When I blocked 3/4'' supply pipe to manifold and left only 1'' pipe, a got water both in the building and the pool. I don't understand what happened. Was it due to parallel piping or something else.
Flow in pipes is mostly affected by the pressure or 'Head' of water at the entry and pressure drop due to friction along the pipes. In low pressure systems problems also arise due to air-locks and minor changes in gradient. Another common problem is inadvertantly forming a syphon in one part of the system.
I hope this helps.