Question
I have a problem with water pressure in all zones and this just happened a week ago. I have a hodrotek 6000 and I'm pumping water from a fresh water canal with a ten year old pump . I've replaced the indexing valve in the hodrotek and clean the insides of the valve . the pump run great do you have any other items to check .

Answer
I am not familiar with the indexing valves so you may what to re issue the question to another person.


General thoughts I have though:

I see that you say the pump runs great. Does mean that you know the performance of the pump is consistent to what it was prior to the low pressure issue?

One thought: Say for example at zone requires 20 gallons per minute and it is only receiving 16 gallons of water per a minute. It will cause the system to operate under low pressure since the amount of water required is not being met.

Another thought: While zone 1 is running do you say any water at all seeping out of the other heads on zones 2 or 3?