HPS grow lights

Light Distances for Growing Cannabis with HID Lighting HID grow lights like Metal Halide and HPS (High Pressure Sodium) are the most widely-used and debatably the highest-yielding grow lights available for growing cannabis. Metal Halide lights are well-suited to the vegetative stage and tend to encourage plants to grow short and squat though they are less electrically efficient than HPS. HPS grow lights are suitable for both the vegetative and flowering stage of cannabis growth and the light they give off encourages plants to quickly grow tall and produce big buds. Despite these differences, MH and HPS bulbs need to be kept about the same distance away from your plants. The proper distance actually depends on the size/wattage of your lamp. In addition to the wattage, it’s important to realize that older bulbs stop giving off as much light over time, so new MH/HPS bulbs generally need to be kept further away and older bulbs should be kept closer than the normal recommendations. ...

HID Grow Lights As stated in our previous article HID, but especially HPS, is the gold standard to which all other lights are compared. They produce intense light in a spectrum that fits the flowering phase very well, leading to reliable and potent yields. The most efficient distance to keep an HID bulb above a canopy depends on the wattage of the light and your grow tent conditions. You want your light close enough to provide energy to the plant, but far enough to avoid heat stress. A good rule of thumb is to make the distance between your lamp and canopy around 10cm (or 4in) per 100W. This would result in hanging a 600W HPS grow light at a height of 60cm or a 1000W at 1m (3’ 8’’). Of course the main reason not to hang a light too close is to avoid burning your plants, but this is not necessarily the most efficient. Additional ventilation or the use of a cool-tube reflector can allow you to position your lights closer. In terms of usable light, somewhere between 30 and 60cm i...