Hi,

Let's do an audit for each area.

Area 1: 1,800 sf x 0.083 ft = 150 cf X 7.481 gal/cf = 1,122 gallons needed per week in the hot summer to irrigate that area.
3 hds x 3 gpm/hd = 9 gpm, 1122 gal/9 gal/min = 125 min of watering per week. 125 min per wk / 3 days per wk
= 41 min per day.
Area 2: 80 sf x 0.083 ft = 6.7 cf x 7.481 gal/cf = 49.7 gallons needed per week in the hot summer to irrigate that area.
2 hds x 2 gpm/hd = 4 gpm, 49.7/ 4 gal/min = 12.4 min of watering a week. 12.4 min per wk / 3 days per wk = 4 min per day.

Someone please check my math. I have not be doing well lately with the math. Of course it is my calculator's fault.

Since the time stays the same for both areas you have to balance to gallons applied per time. Your system is designed for the small area at the expense of the big one. You probably need to increase the nozzle size of the 5000 series to give the needed amount of water within the time of 4 minutes. My guess is you need some extra heads in the big area to also improve your coverage.

You can do an irrigation rainfall audit by placing cups out on the lawn. Run your system for a certain time. Measure the depth of water in the cups and estimate your system running time to obtain 1" of water coverage per week. This also shows up any spots not getting as much as other spots. It is a irrigation intensity plot for your yard and you can add or subtract heads to take care of those spots. If you don't need an inch a week amount then the difference is less pronounced. JMHO and hope this helps. Aloha

Thanks for the help and calculations. My water system is only approx 14 GPM, and the system pressure is 55 PSI with everything shut off. Zone 1 has another 3 heads which overlap with zone 2 (the one we are working on). I have good head to head coverage with all 6 of the 5000 series rainbirds. Yesterday I picked up a single center strip head that claims 4'x20' coverage at 2 GPM. I think it is still more water than I need compared to the area the 5000 series are now watering, but now that I know how to calculate it, Ill go home and figure it out. I do have a 3rd zone going under the side walk to water a large (2'X20') flower box, it has 2 GPH drip heads on the whole zone. Maybe I should landscape the 4X20 patch of lawn into flowers and throw in another couple drip heads on zone 3...its hard to mow with the rider anyway :-)

Hi drudge,

Your welcome, Glad I could help. You could isolate the strip areas pretty easily with their own automatic valve and small 3/4' line. This preferable with such drastic different types of heads. You have very good pressure so there is not problem there. You have many options good luck. Aloha.