I have seen red warnings at a future time on occasion. But the levels did not reach the warning limit. This is probably based on a "better safe than sorry" algorithm in the software to bring your attention to a potential problem. For example, if there is a spike in temp, it would trigger a potential warning in a time frame in the future. As far as lighting, the light sensor on the Seneye is on the back and meant for measurement with user intervention. For example, you would take the device and hold it with the light sensor facing the light and take readings in different areas and depths. This can be useful to check when as lights age, they produce less light and need to be replaced. The light readings will always be red unless your Seneye is oriented with the light sensor up at all times. It does not mean you need your lights on for a longer period. More than 8 hours would be asking for trouble with algae.
Seneye's response on Oxygen levels:
"The Oxygen reading is the maximum theoretical oxygen content of your water. This is based on the water parameters and mainly temperature. As the temperature increases, the water's ability to hold oxygen decreases. The reading given is theoretical because we do not measure it directly, so when you add fish etc it will decrease.
There is no real good range as such. The basic rules are, if the temperature goes up very high you may want to concider increasing circulation. The measurement has most use in ponds where temperature control is much more difficult than in aquariums."