The hours between midnight-5 am are best to water your sod. Avoid, if possible, watering into the evening hours (after 5:30-6 p.m.) because this is the best way to avoid a fungus problem. Too much water will rob the roots of oxygen and in warmer weather that can possibly lead to disease. The length of each watering cycle will depend on the soil type with which you are working and the output of your irrigation system. A clay type soil may need five minutes, four times a day and a sandy loam may need seven minutes, five times a day. You have to judge the minutes given, but here is a tip: If the water is standing under the sod for more than just a few minutes after an irrigation set has finished or if the soil is soggy, you are probably giving the sod too much water at one time. After the sod is established, you can reduce the amount of times per day that you water the sod and you can increase the length of watering minutes.