Photocell question

I have the 7094 Controller with the photocell and 2 Turbelle 6110 pumps. After installation today, the photocell does not seem to operate. The controller continue switching between A&B after the lights are off. How sensitive is the photocell. I have an open refugium under the tank with 24/7 lighting and some light escapes . Even when I cover the sensor with my hand nothing changes (that is one pump should work at low speed).
Do I have a defective photocell. How can I test it?
Most of the time it is not firmly plugged in. It is reasonably sensitive. At least covering it with your hand should trigger a change. I am in germany and don't get back in the office until Monday next week. Please remind me if you cannot resolve the problem and we will exchange the photocell. Also make sure photocell operation is correct for the program you choose- read the manual.
Thanks for the reply. I re-connected the photocell and it works now. I have it about 25-30 cms from the metal halides and my Blue Actinic PC. Of interest is that the photocell does not respond to the PC lifgts unless I place it about 5 cms below it! My setup is such that the actinic lights come on at 8:00 AM, MH at 9:00 Am then MH shut off at 8:00 PM and actinics at 9:00 PM. What is the recommended period for low flow at night?
No real recommendation- think of it as a toy. We had a brainstorming session and came up with over a hundred toys- some were really far fetched. As Axel says we work for men and we build toys for them- it is really that simple. Everyonce in a while a toy becomes a technical brake through but night mode really isn't one of them. In theory nightmode is similar to the effect of the high tide and the seas calm at night, it should stimulate a feeding response in the corals and a plankton swarm. Nightmode should be used with some caution- though it is the normal way of the sea, in the confines of an aquarium excessively low flow may cause excessive night time pH drop. Just something to look out for, otherwise play around and enjoy.