[quote]Originally posted by David
[b]I've recently purchased the necessary Tropf Blumat parts to build an
irrigation system. I want to irrigate grow-bags using a single sensor
and three or four distributor drippers. However, I'm finding that the
dripper nearest the sensor is delivering about twice as much water
than the next

To even the pressure between the drippers create a loop in the dripper tube by using a 'T' after the sensor. Put the drippers where you want them in the loop, remembering to put one the required distance from the sensor. The inspiration for this, (no reason you should care, but just in case!) is electrical ring mains. Incidentally, using a ring main enables cabling to carry more current than would be the case in a radial installation, so this will assist the Tropf Blumat to deliver water more efficiently too - useful with the low pressure you have.