clam and lighting

[SAreefer]

I would like to have someone explain the following to me - I am running 6 x 54w t5's, 3x 20 000K and 3 x 10 000K. When I switch of the lights(one at a time) the clam is not affected(does not retrack) when I switch of the 10 000K bulbs, but makes alot of difference when I swith of just one of the 20 000K ones. Please explain.

 

[Anonymous]

Put the 20 K's on first, which simmulates dawn. When you turn them on after the clam thinks there is a shadow and makes him retract as if you put your hand in the path of her light. It is a defensive mechanism.

 

[fungia]

i think your clam is sensitive to the spectrum that the 20k make. or maybe the 20k bulbs flicker in a different when when you turn them on that we dont notice but the clam does.