SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I recently installed an underground drip system in my back yard to try it out before attempting an installation in my larger front yard (smart thinking). So far, the results have been less than satisfactory. The soil is medium sandy soil and I'm using 1 GPH drippers spaced 12" with 12" laterals. I've set my timer a minute or two above the evapotranspiration rate for my area (Ridgecrest, CA). When I initially installed it, I had a 30 minute runtime and noticed that water was running out of the retaining wall in some spots and gradually adjusted to the eTo rate. I've tried watering the yard once per day and even broken it down to twice per day, but it seems the grass (tall fescue) doesn't get enough water in the non-shaded areas. I'm afraid that since I installed the tubing by hand, I may have compacted the soil a bit. What would you recommend for an irrigation cycle? It seems if I don't blast it with water for a consecutive longer period of time, the grass dies, but given the upper layers of the soil drain so fast, I would have to take that approach more often, also resulting in a higher use of water.

My problem may also be due to other factors, so I have also included the results of a soil test: Soil pH(8.0); Buffer pH(7.6); P(42 PPM); K(123 PPM); Ca(1698 PPM); Mg(128 PPM); Mn(6.3); Zn(.9); B(2.9); Cu(.4); Fe(2.4); S(77.9); Cation Exch (9.9); Base Saturation(K-3.2%, Mg-10.7%, Ca-86.2%), and organic matter at 1.7%. I plan to correct this by adding Ammonium Sulfate (24-0-0-24) (3 lbs/1000 ft) and Elemental Sulfur (3 lbs/1000 ft) twice a year, 10 lbs Ironite/1000ft twice a year, and 1/4" top dressing (mixture of Kellogg N'Rich, Steer Manure, Earthgro topsoil, and Earthgro potting soil). I can rent an aerator for my front yard, but since I only placed the drip 4" deep in the soil I'm stuck with doing the the back yard by hand.
Any recommendations would be appreciated.

What would you recommend as an ideal spacing for sandy soils? When installing it, I attempted to stagger the lines so that drippers for the next lateral didn't line up but where centered between the drippers from the last line.