Hi there. I'm making a return to planted tanks after a long lay off. I've dusted of my needle valve, bubble counte etc and gone and bought a new cylinder. Everything is in place and I'm turning on the co2 2 hours before lights on and turning it off 2 hours before lights off. I've not had a planted tank using co2 since the mid nineties and I know a lot has changed since then. I've tried to learn as much as possible but I'm still stuck on light duration. Back then all the books seemed to recommend 10-12 hours light (they recommended a lot of nonsense it seems such as cable heaters, mid day siestas etc). Just wondering what is the minimum and maximum light duration I'm looking at?