I have a hypothetical question. I'm not sure exactly how to phrase it, so I'll ask it through an example. Part of me thinks it's a stupid question, but I want to be sure.

Let's assume that for the plants in Tank X, the ideal lighting is 100 watts for 8 hours a day. Assuming all other variables are equal, would the plants recieve the same benefit from a 100 watt light for 8 hours a day as they would from recieving 50 watts of light for 16 hours a day?

The reason I ask, I'm fiddling with the length of my light cycles, trying to find the right balance, and wanted to know if using half the power of my lights for part of the day truly equals half the benefit to the plants.

To rephrase it another way, is using half the wattage for 2 hours equivalent to using full wattage for 1 hour?

Thanks in advance for any help.