|Ultimately the reason to watch Bijou is in the hopes of seeing a Giant Hot Period. Thus the observer is looking for a two or more minute stop in Bijou's activity.
Bijou stops for three different reasons:
First - Bijou stops during Giant's eruptions and does not restart until the system has started to recover from the eruption. The amount of time it takes for the system to recover can vary greatly but it usually takes over eight hours for the system to recover to the point that Bijou restarts.
Second - About five to six hours into a long mode eruption of Grotto Geyser (a Marathon eruption) Bijou will slow down and eventually stop. Bijou usually recovers and restarts about 4-6 hours after Grotto stops. During periods of frequent hot periods, Giant will often have a hot period at about the time that Bijou recovers.
Third - Bijou can have a PAUSE in its activity. A pause occurs when all splashing from Bijou stops. Assuming that Bijou is not pausing for either of the first two reasons, the reason that Bijou pauses is because the water levels on the Giant Platform are rising. The initial stages of the rising water can be hard to see from the boardwalk but Bijou's Pause indicates the rising water levels. Eventually, if the pause lasts long enough, the rising water levels can be seen in Mastiff Geyser and if a hot period results, in the many platform vents.