City of San Diego Water Department - Landscape Watering Calculator Micro-Spray Micro-spray sprinklers are just like regular spray sprinklers only smaller.  They are made of plastic or brass and attach to pop-up bodies or to flexible polyethylene tubing.  One advantage of a micro-spray system is that water is able to soak into the soil more slowly, preserving the air/water balance in the root zone and reducing runoff.  These systems are ideal for very small planter areas because the spray pattern can be precisely adjusted.  Distance of coverage is from 1 to 15 feet.  Proper filtration and pressure regulation is required.  The operating pressure range is 15 to 30 p.s.i.