As a hobby, hydroponics certainly comes with its fair share of kit. Some items of equipment are crucial for the running of the system, and some are simply useful add-ons that improve functionality.

Lighting is often plugged as an optional extra, but the truth is that although plants will develop adequately in a good natural light source alone, they won’t reach their full growing potential. Lighting systems are an excellent way of giving crops an added boost to guarantee a fantastic harvest.

There are a variety of lighting setups available for hydroponic gardens. Choosing the most suitable setup can be overwhelming, but a little bit of research goes a long way, so get your thinking cap on and knuckle down.

The most important factors are light intensity and colour spectrum. Plants not only need a certain amount of light to grow, but in order to photosynthesise at the best rate possible, they also need to absorb a certain amount of red and blue light. In an ideal climate, they would assimilate this naturally from their environment, however, in hydroponics, it must be provided separately.

Incandescent Lamps

Incandescent lamps are basically standard household bulbs. As they are inefficient and generate a lot of heat, they are a poor choice for plants. However, they are a good reference point when comparing different types of hydroponic lighting, especially in terms of light efficiency and intensity.

High Intensity Discharge Lamps (HID)

HID lamps are the most common type of hydroponic lights. Their lumen per watt rating is high, meaning they have a high light output and can be up to 8 times more effective than traditional incandescent bulbs.

A typical HID setup includes-

  • A Bulb (either metal halide or high-pressure sodium)
  • A Ballast (a resistor that regulates the current through the bulb)
  • A Lamp Holder
  • A Light Reflector (which diffuses the light and heat evenly)

Metal halide and high-pressure sodium are the most popular HID lights. Metal halide light is predominantly blue, which is beneficial for shorter plants and strong vegetative crops. High-pressure sodium lamps emit light that is mainly red, promoting flowering. Combining the two offers the best colour spectrum for plants. Unfortunately, both lamps require separate ballasts and lamp holders so using them together is an expensive option.

On their own, high-pressure sodium lamps are more effective than metal halide, so some gardeners choose to use them alone throughout the growing cycle. However, this can cause an imbalance which leads to spindly plants. Thankfully, blended light lamps are available which emit a balanced spectrum of red and blue light, eliminating the need for separate ballasts and lamp holders.

The downside of HID lamps is that they produce a lot of heat. Proper ventilation is vital to diffuse this warmth, and lights should always be hung at least 2 feet from the top of your plants to avoid scorching.

Fluorescent Lamps

Fluorescent lamps, especially T5 high output bulbs, are the perfect light source for smaller plants. They are up to 7 times more effective than standard incandescent bulbs. Fluorescent lights usually fall into two categories- strip lighting (SL) or compact fluorescent lighting (CFL). They are available in a variety of spectrums, allowing the grower to provide a range of colour temperatures to suit different stages of the growing cycle. Do your homework here and you will really maximize your yield!

Fluorescent lights don’t emit as much heat as HIDs, so they can be hung nearer the plant. Unfortunately, they are not as penetrative, so are unsuitable for larger plants.

Fluorescent lamps produce multi-directional light. Use in conjunction with a light reflector for maximum efficiency.

LED Lights

LEDs are a more expensive lighting option. However, they have a longer lifespan and use less electricity than HIDs and fluorescent setups.

It’s worth noting that in the past, LEDs weren’t given much weight as they were unable to deliver the spectrum of light necessary for growing vegetable crops. However, thanks to advances in technology, LEDs can now deliver the colour spectrum required by vegetables and fruit plants.

The market is flooded with cheap, poor LEDs so it’s important to study the different brands and learn which ones are best. Don’t get caught up in the false economy of buying a shoddy ‘bargain’. If you’re serious enough about your crops to consider LED lighting, then be prepared to fork out for it. Otherwise, stick to HIDs or fluorescents.

Choosing a Hydroponic Lighting Setup

Budget and purpose are the main elements that will influence your choice. For amateur horticulturists who are just testing the hydroponic waters with small scale crops, T5 fluorescents are an efficient and inexpensive selection.

For more adventurous growers who have a larger area to cover, HIDs offer better light cover. However, for enclosed spaces, you will need a proper ventilation system. It’s not much good giving your plants the light they crave if you are killing them with heat, is it?

Large scale gardeners who are in it for the long haul are more suited to LEDs. The electricity savings may seem like a drop in the ocean on an ongoing basis, but over an extended period of time it really adds up and can save you thousands over the years.

Maximizing Light Intensity

It’s not just the type of lighting that governs the light intensity of your setup. Getting the lamp size right is vital to maximize light conditions. More expansive growing areas thrive best with larger wattage bulbs.

Avoid placing plants too close to one another as this creates shady nooks that light cannot penetrate. Hang your lamps as near to the crop as possible, without risking scorching or damage to the leaves.

Plants prefer a consistent light cycle, with most species requiring 12-18 hours of light per day. However, the exact amount that they favour depends on what stage of the growing cycle they are at, so be sure to study each individual plant to confirm the necessary conditions.

Light reflectors are optional but they infinitely enhance the effectiveness of your lighting.

Hydroponic newbies often question the necessity of lighting systems. However, any seasoned gardener will tell you that a good lighting setup can transform an average harvest into a bountiful yield. Well worth the investment then!