 Hi everybody! As you can see, the lighting is a little bit different today because all of the grow lights are on, but I thought it was very fitting to talk about how long to keep them on. So yeah, let me tell you what I've learned. Okay, before we start, I wanted to let you know that this is part 4 of a series on grow lights for houseplants. So if you would like to see all of these episodes right here, make sure to check out this link right here and yeah, I hope that you like it. But now, let's get to the question. How long do we keep our grow lights on? You know, generally our plants like to have 12 to 16 hours of light. So generally, I would recommend that you follow these rules. This can be of course all natural light, a combination of natural and artificial light, or completely light that comes from artificial light, which means light that comes from grow lights. So if you're giving your plants 12 hours of light a day, I would recommend that you measure the hours of adequate natural light that your plant receives at day, and then see how many hours you have to supplement with artificial light. Now, having said that, different plants will have different light requirements. And these depend on some factors that we should consider. The first thing I look at with my plants when I'm deciding how long I will keep my grow light on is their for a period requirements. So what is for a period? For a period refers to the time of light and darkness, a plant needs to thrive and flower. The plants that are affected by the periods of light and darkness during the day when it comes to their growth or flowering are called photoperiodic plants. Photoperiodic plants will fall into three categories. The first one is long day plants, and these ones will generally need 12 or more hours of light to flower and thrive. Short day plants, which by the same logic, then they will need less hours of light to thrive. So this is maybe 10 or less hours of light to flower and thrive. And then we have neutral day plants, which basically are okay with 12 hours of light and 12 hours of darkness. Okay, so how do you determine your plants for a period? There are two key factors that can help us determine which type of plant our plant is depending on for a period. The first one is where does your plant actually come from? If we think about it, this is very logical. If our plants come from a region that is close to the equator, these plants will be most accustomed to days and nights that are almost of equal length the whole year. As you get farther away from the equator, how long the days and the nights are will depend on what season of the year it is. For example, here in Berlin, we get shorter days during the winter and longer days during the summer. So if your plant originally comes from a region that is farther away from the equator, it will likely be a short day plant or a long day plant because they have to accustomed to the different seasons in the year. Another thing that you can look at is when does your plant naturally flower? If you know that the plant that you have naturally flowers in the summer, this most likely means that your plant is a long day plant because it needs longer days to flower. Some good examples for long day plants include the sunflower or the petunia. Now, if your plant naturally flowers in the winter, it most likely will be a short day plant because these plants need longer periods of darkness and shorter days to flower and thrive. These, for example, can include the poinsettia or the Christmas cactus. So for your reference, and you can screenshot this part of the video, here are the light requirements per plant depending on their photo period. And in the guide that I have just published on life for houseplants, I have also included a list of the 50 most common plants at our homes, their light requirements, as well as their photo periodic requirements. So if you would like to check that out, make sure to check the link in the description down below and I hope to see you there. So how can you set up the time for your grow lights? There are different ways to do it, so let me show you. First, you can always get a grow light with a timer like this one. So as you can see here, we have three, nine, and 12 hours. So depending on your plant and how you're using your light, you can decide what time you want here. And all you have to do is you turn it on, and then here you press this clock right here. So as you see here, it's flashing. So right now it's flashing in blue. That means that it's going to be three hour timer. Then this is nine hour timer and 12 hours. Now I can tell you one of my favorite grow lights right now is from Soltec Solutions. This is the Aspect LED grow light. It's really beautiful and it's kind of like a spotlight fixture. So it's really nice, but it's a very good grow light. Now the quality is amazing, but if you buy this grow light outside of the U.S., it doesn't come with a timer. If you buy it in the U.S., you could get it with a timer, which is really nice. But since I am in Germany, I could only get it without a timer. So if you really like a grow light, like I like this one and it doesn't come with a timer, it's not a problem. You can always just add your own timer. This one you can get in Amazon. I really like this one because you can program it 10 times. So this is what it means. For example, here I have timer number one. This one is from Monday to Friday from eight to eight, so 12 hours of light. But then I have program number two. This one is on Saturday and Sunday, and this is because it's in our bedroom. So I put it a little bit later. It's going to turn on at nine and then it's going to turn off at nine o'clock in the night. And all you need to do is plug it in like so. And this is for the grow light. There it is. Thank you so much for watching. If you have any other questions, make sure to comment below so we can keep the conversation going. Also, don't forget to check out this playlist right here where I have all of the episodes related to grow lights. And as always, I will see you in the next one. Okay, adios!