Oh I definitely tried it but my version is 6hrs on / 2hrs off. 6hrs on / 2hrs off. Etc etc, and I have noticed increase in vegative growth. But it's nothing compared to the 12hrs on /5hrs off. 2hrs on /5hrs off, for veg growth.Then use as little as 8hrs on and 16hrs off for flower and see a harvest in about 20percent less time. Not to mention that the oil production is much higher due to the extra 4hrs of night time, bc a lot of the oil and phytochromes are produced at night. Not during photosynthesis. Also there's an advantage to be spoken of in the plants themselves having much lower levels of stress due to the more natural light cycle. Nowhere on this planet can you find 16 to 18hrs of direct sunlight, thus no plant that evolved here will have the million year old genetic code, which finds such long hours condusive. In fact they're more likely to be highly stressed and exhausted from being over worked. This method uses 20% less time and 20% less energy, not to mention it gives you a little stealthiness when it comes to the Electric company who are looking for a certain 12 on 12 off pattern in energy usage.