Answer: If water is puddling in the lawn, you'll want to fix the problem. Start by changing your watering pattern. 90 minutes seems excessive. If you can set your system for 15 mintues twice a day, every 3 days it should provide enough water; if not, set it for 30 mintues every 3 days. If this doesn't cure the puddling problem, you may have to dig the sod up from the low places, put some top soil in the spots that puddle, and reset the sod. Fertilizer won't help solve a fungus problem, but a fungicide will. Try changing the watering pattern first; if the lawn looks water stressed, water every other day rather than every 3rd day (the idea is to provide a deep soaking without having puddles).
Best wishes with your lawn!
Q&A Library Searching Tips