Hi Peter
Coming late to this conversation.
You mention using a venturi with a 1354.
I'm using a similar system. Water from borehole with a venturi (with a partial flow bypass) drawing ozone in and then a 1354 with DMI65.
The problem is I don't get enough pressure differential across the venturi to make it draw ozone. To solve this I have another pump in the venturi line to boost the pressure.
It feels like the 1354 creates too much "back pressure" for the venturi to work hence adding the extra pump.
I'm also off grid for electricity so need to minimise power and would love to ditch the extra pump.
Any thoughts, am I missing something obvious?
David