Giving lighting manually to a fish tank is a very difficult task. Though you can get it right on some days there will be days where you can easily forget to turn your lamp on or off due to several reasons. Ultimately it will end up affecting health of your fishes or may even result in death in severe cases.
The best practice is to buy a timer that automatically turns lamp on or off as per the instructions. It will help you to Stick to a real schedule of actual sunrise and sunset and ultimately will keep your fish happy and healthy. Just figure out how much amount of light you species of guppies requires in natural habitat and set it on the timer and you’re good to go. For Guppy fish i think that any type of lighting is going to work as long as you can give them a substantial amount during the day, So that they can have clear visibility. I would advise going with the fluorescent set up or LED lamp because they use less power and they give off a lot of light.
