Why are my lights doing this!!??

I just noticed that my 400 watt hps/mH keeps dimming and getting brighter every few minutes. I have my ballast/light, timer, and 12vlt dc with two fans plugged into a power strip that is plugged into a orange power cord. The fans and my humidifier are plugged into a brown ext. cord. Will the light changing like that affect my babies growth? How can I fix the problem?

mini surges probably caused by something else on the circuit.

Will it affect my ladies in any way?

probably nothing noticable, but it might decrease the life of all the things plugged in to the circuit