There are a lot of variables.
I have 25' of 5/8" plastic tubing that goes from the pump to about 30' of 5/8" weight hose. The weight hose meets a 3/4" PVC "T". The 90% part of that diffuser goes to one diffuser. The straight through end of the T connects to about 4' of PVC pipe then hits an elbow on which the other diffuser is connected. To make things even more interesting, one diffuser has been used a year while the other is new.
We're getting some much needed rain today, but as soon as conditions allow I'm going to go do some more experimenting to see what's going on.
