Working Around Rain Bird STPi600 Preset Watering Intervals

Understanding the STPi600's Fixed Start-Time Logic

The Rain Bird STPi600 controller uses a unique preset interval system: when you set a start time, additional start times are automatically spaced at fixed intervals (4, 6, or 8 hours). This can conflict with watering restrictions, such as a ban from 10 AM to 6 PM.

Why You Can't Override the Intervals

The controller's firmware does not allow independent start-time programming. If you set one start time, you get one cycle. Two start times forces a 6-hour gap; three forces 4-hour gaps; four forces 3-hour gaps.

Practical Workarounds

1. Start very early: Set a single start time at 2:00 AM with longer run times for deep watering.
2. Use an evening start: If multiple cycles are needed, start at 6:00 PM. Four cycles at 3-hour intervals end at 3:00 AM, well before a 10:00 AM restriction.
3. Reduce frequency: Water deeply but less often to minimize cycles.

When to Consider Replacement

If your watering schedule cannot be met with these constraints, upgrading to a controller with fully programmable start times (e.g., Rain Bird ESP series or Hunter Pro-C) provides the flexibility you need.