autoflowering cannabis grow light

Growing Autoflowering Cannabis Under HPS Light

An HPS lamp could be the most popular growing lamp of choice among experienced cannabis growers because of its amazing benefits and features. HPS is short for high pressure sodium; these lamps produce very intense light that no other artificial light source can with. It is so called because sodium electrons are contained in very high pressure to create a glow that looks like an orange/pink sun that radiates huge amounts of heat. At this color and intensity, HPS lamps have a very high luminous efficacy with a light to energy ration from 100 to 200 Lumen/Watts. This value is quite high compared to regular light sources like incandescent light, fluorescent light, TS and metal halide lights.

Because of these amazing qualities, HPS lamps are recommended for mid to large scale autoflower growing. It can be used to cover a large amount of space and provide quality, efficient and reliable artificial lighting that can provide better and larger yields. However, there are also small scape HPS lights with small wattages for small grow rooms. If you can manage the heat produced from HPS light then you will be able to harness this amazing energy and grow cannabis plants that will provide more yield compared to any other light source.

Unique Features of HPS Lights that Growers Need

  • Color temperature – HPS lamps emit mostly yellow light which is found at the end of the visible light frequency. This makes HPS lights better at the flowering stages rather than the seedling stages of cannabis plants. During the first few weeks, cannabis seedlings need mostly blue light to develop strong and healthy leaves, stems and roots. But as it moves from the seedling to the flowering phase, it needs more yellow light; this kind of light mimics the color of the bright sun as it turns yellowish red to signal that summer is about to end. This color also benefits plants snice the small photosynthetic pigments in plants that absorb red light trigger the plant’s flowering stages than influencing its overall growth.

Under an HPS lamp, an autoflowering plant will become stretched and strong because blue light here is absent. Blue light is important for the seedling and vegetative stages which is why many growers start using MH lamps or fluorescent lighting to create blue light.

  • HPS lamp wattage – there are a number of lamp wattages to choose from ranging from 70W to 150W. For indoor cannabis growing, 150W, 250W, 400, 500W to 1000W are used. Stronger bulbs equals to more growth. Smaller bulbs are meant for smaller grows or smaller grow rooms but still these small bulb wattages are more efficient than using fluorescent and incandescent lighting.
  • Heat emitted – because HPS lamps are so powerful, these emit large amounts of heat which could be detrimental to plants especially if you have a small grow room. Growers use ventilation systems and oscillating fans to remove heat from their grow rooms. The higher the bulb wattage, the higher the more heat it will produce. It is also critical that plants are prevented from stretching as high as the HPS lamps since these could burn the plant’s delicate stems and leaves. Oscillating fans can help reduce the heat of these lamps and prevent accidental burning.
  • Lamp and plant space – usually HPS lamps and cannabis plants should have at least 6 to 15 inches space depending on the lamp wattage and the growth stage and strain of the plants. Strong 150W HPS lamps may be as close as 6 inches to your plants without causing burns. Therefore, stronger wattage bulbs need to have more space between them and the plants. A good way to measure heat is to place your hand just below the bulb. If the temperature is OK for you then your plants will also be OK as well.

A closed reflector case may also be used to get plants closer to the HPS lamp without affecting the overall temperature of the room. Hot air will be ventilated from this case.

  • The cost of using HPS lamps – possibly one of the downsides of using this kind of lamp is the cost. Definitely a single lamp allowed to light autos for a good 16 hours a day can leave a hole in your wallet. But what if you used it for 24/0 lighting schedule? This will eat a huge fraction of your profits! The best thing to consider is to follow an efficient lighting schedule and give your plants some dark time which can give your lamps a rest as well. You can install a lamp timer to program your lamp to power on and off as you wish.

There are a lot of good HPS lamps online. You must check these factors out and do your own research and comparison to get the best lamp for your needs.

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