Types of Grow Lamps
Knowing what type of grow lamps you're in need of is very important, as they each have their own job to play in your grow room, and some lamps will only work in certain lighting systems. Understanding how much light is required is also very important, as getting the light intensity correct will help you push your yields up.
HPS (High Pressure Sodium) Grow Lights
This is a type of HID grow light and used to be the standard type of light for flowering and fruiting. They consist of a grow lamp, ballast and reflector. They work by exciting a sodium gas inside an element (arc-tube) inside the grow lamp. The light the grow lamps emit has an orange-red colour to it which is great for producing big yields. A 600 watt model generally covers an area of 1.2m x 1.2m while a 1000 watt model is better suited to a 1.5m x 1.5m area. There's quite a few different models of reflector. The better the reflector, the more light it will reflect back down onto the garden, and the more evenly it will light the canopy. There's a choice of cheaper magnetic ballasts or more efficient (and cooler) digital ballasts which usually boast a dimmer and boost facility. HPS lamps go from very cheap to very expensive. The key to them is that you get what you pay for. The better HPS grow light produces more light and have a slightly broader spectrum. The high frequency 400 volt HPS lights, such as by Dimlux and Gavita grow lights, are the very best types of HPS and provide a step up from the standard types in terms of efficiency (light output per watt) and spectrum. The downsides to HPS grow lights is that they run very hot (the lamps run at several hundred degrees Centigrade ,ºC) and they produce infra-red. The result is that the grow space can become hotter than the ideal temperature for growing plants. HPS lamps are also less efficient (produces less light per Joule of electricity) than the recent crop of premium LEDs. If you're using HPS, use a Philips lamp for maximum growth.
CDM / CMH Grow Light
CDM grow lights (Ceramic Discharge Metal-Halide), sometimes called CMH (Ceramic Metal Halide) are the modern version of the old HID MH type of light which is less popular these days. CDM grow lights produce full spectrum light and produce high quality crops. Like HPS light, they use an element (arc-tube) filled with a gas that is excited by the power provided by a balllast. They are often used alongside HPS grow light to fill in the spectrum where HPS grow lights lacks. They are still HID lights, though, and because of this they do produce quite a lot of heat. Many growers use one 315w grow light between 2 600w HPS light. Many growers swear by them; remember that CDM lamps do not have an E40 connection like HPS or MH lamps. Instead they have a bayonet fitting which means that you need to get a reflector with the correct fitting, or use a converter with that style of grow light. CDMs are very compact and come in a few different wattage options. We'd recommend using them in-between two HPS lights to maximise your plant growth (you'll also add a blue spectrum into your grow area with the CDM lamp).
If you want a more efficient full spectrum of light, don't forget you can always choose to grow with led light. LED light is a mix of red and blue light, giving you the perfect light spectrum for increasing vegetative growth and piling on weight during the flowering stage. Fuelling your indoor gardening habits with an LED light is also a more cost effective way to add the natural light that your indoors plants require. LED grow light is also fantastic for those who're wanting to get the benefits of a CDM but want to keep the heat down in their indoor garden. As artificial light goes, it's the closest you'll get to direct light from the sun as natural white light is what your plants are genetically geared up to grow best under. It's fantastic even for young plants as you can dim down the LED light levels to match the stage at which they're at. LED lights also don't require you to change your light bulb, making it even easier to create an easier environment to work within.
Metal Halide (MH) Grow Lights
These are like the old version of CDM HID grow light. The element in an arc-tube is filled with a metal halide gas. A ballast, grow lamp and reflector is required just like HPS. They produce a blueish white light that makes them great for vegging plants under. Unfortunately, they aren't very efficient and they produce a lot of heat (even more than a similar wattage HPS grow light). We'd recommend you go for LED or CDM light instead of MH as the full spectrum gives you a much nicer output which your plants will love.
Types of Light
Red and Blue Light
Red Light - Red Light is best suited to piling on plant growth during the flowering stages of a plants cycle. HPS is well known for being the king of red light, but modern LEDs have hit the nail on the head in terms of far red light.
Blue Light - Blue Light is best suited for supplemental lighting or throughout the vegetative stages of a plants growth. Indoor plants require a mix of both red and blue, and blue speeds up leaf growth and height. Supplemental grow lights consist of CDMS or LED technology.
To see our full Grow Lights range, click here