Grow lights are available in an incredibly wide amount of prices, sizes, and styles.

Before you make a purchase decision, you may want to consider these guidelines to consider before buying grow lights:

1. Space Available
 One of the most common questions beginning urban farmers ask involves managing limited space when starting an urban farming project.

If you don't have the space to operate a certain type of grow light, you won't be able to use it.

The reality is that different grow light types will require different amounts of spacing in between the bulbs and fixture and the plants. If your plants are too close to the lighting, they will at the very least have lower yield and may even literally be burned.

When space is efficiently used with grow lights, vertical farming stacks can also be feasible by creating multiple layers of plant beds and grow lights.

Do get an approximate idea of the space you will need vertically, see the tables below for LED (light emitting diode) and HPS (high pressure sodium) lighting. At the end of the day, the spacing necessary will have a lot to do with the strength of the light - the stronger the light, the more space needed is a fair rule of thumb for urban farming beginners who don't want to over-complicate planning.

2. Heat and grow lights
One of the major components of indoor growing is the temperature inside. Generally speaking, most types of grow lights will generate heat:

High Pressure Sodium / Metal Halide: will generate significant heat, must use in unison with fans or other tools for ventilation.

Fluorescent: will not generate as much heat as other grow lighting options, but still significant.

LEDs: extremely minimal heat, in most cases, you will not need to factor in any temperature differences if you are using LED grow lights.

Tip: Most content online will discuss the downsides of heat, the preventative measures required with grow lights that generate heat, and how to prevent overheating. However, for many urban farming beginners, risk of temperature becoming too low can be decreased by using a grow light that generates some heat.

Keep in mind that just because a grow light adds warmth, you will likely need to take other steps if you are growing in a particularly cold room (< 20 C or 70 F). Some options include tenting for insulation or heating pads.

3. Know the key grow light specs
Grow lights have 3 primary attributes to consider:

intensity: Lumens are a measure of a light's intensity or brightness, however this measurement is designed to quantify human visibility, not plant visibility.

The metric to consider for grow light intensity for urban agriculture is Watts (W). Generally speaking, the higher the watts, the better.

Light wattage is a key indicator of light pricing, so managing the cost-wattage trade off for your first grow light system is important.

Color: certain color spectra are better for growing plants than others. "Red" and "Blue" light spectra are ideal for plant growth, with red being associated more with the flowering stage of plant growth and blue with the vegetative stage. color is measured by wavelength (nanometers).

One of the biggest advantages of LED grow lighting is that it has highly customizable wavelength capabilities without changing fixtures. This results in the ability to custom-tailor the light regiment for a plant in order to create optimal qualities like flavor, texture, or even plant color.

A related metric is color temperature, measured in Kelvin (K). Keep in mind that for fluorescent CFL lights and T5,T8,T12 fluorescent tubes, color temperature will be listed on the packaging but not wavelength.

Day-length / Rated Life: A last important spec to consider is rated life of your lighting and how that coincides with not only your budget but your "day-length", or how long you are using your grow lights on a day to day basis.

4. Budget

The good news for grow lights is this: there are a lot of options at all price points.

$: CFL bulbs: can be for less than 10 USD

$$: T5, T8, T12 fluorescent: good value for less than 100 USD. A 4 tube T5 grow light system can generate multiple hundreds of dollars worth of produce in a year (1-2 year pay back period with all other costs factored in besides lighting).

$$$: LED and High Pressure Sodium (small sizes): most LED solutions will be on the pricier side relative to fluorescent, if you are going to spend on LED's, your best option is to invest in a light from a well established LED vendor (full explanation in the next section "Vendor Quality")

$$$$: Most heavy duty commercial style systems will involve high pressure sodium/metal halide (collectively referred to as HID or high intensity discharge)and high priced options are increasingly now appearing for LED systems. These systems will range in the thousands of dollars+ (USD) and will often be part of larger systems involving grow tents, grow "boxes", air filters, fans, controlled environment features, etc.

5. Vendor Quality

With grow lights, the technical specs in reality often are not as advertised, even for a brand new product.

When you are paying for grow lights, a lot of what you are paying for is wattage, so this is a serious risk to consider when buying grow lights. This sort of issue could cost you hundreds if not thousands of dollars, and, most importantly, time, if undetected.

Solution: trusted brands like our website may have more expensive products.

6. common grow light accessories
Often times a grow light will be the only part of the "package" or "kit" you are purchasing. Here are other potential additions besides the grow light that you should know about:

ballast/fixture: grow light systems require an electrical component called a ballast to regulate the power supply in the grow light. if you are buying just a bulb, of course you will also need a ballast. this is a necessary component for lights. ballasts can be purchased independently from grow lights but grow lights can also have the ballasts incorporated into unit.

grow tents: grow tents are another feature mainly seen with more expensive systems. Tip: It's worth noting that many of the benefits of a grow tent that help create a more controlled growing environment can be replicated cheaply DIY (not all the benefits).

7. Know the unit economics
Awareness of the cost per unit area required to light your crops is a good way to compare different grow lights and prices.

8. Scalability
If you're planning on starting with a small growing operation but think you may eventually work up to selling your crop to restaurants, you need to keep in mind the scalability of the grow lights you are purchasing.

Other questions to consider:

How will the power requirements of your grow lights change at scale?
How will the unit economic cost change?
Will I be able to effectively grow at scale with this type of grow light only?

9. Safety
Not all grow lights have the same safety risks.

Two key areas to evaluate with grow light safety are 1) how fragile the light is, and 2) the materials that are present in the light itself.

In both of these categories, LEDs have a clear advantage. For household growing projects where pets or children may be disturbing the lights, LEDs are much less likely to break when knocked down or jostled, due to the small size of the diodes and the way they are situated in the fixture.

Other lighting systems like fluorescent tubes and HPS lighting can be very fragile and will shatter or even explode if they are knocked over with enough force.

Additionally, mercury is present in fluorescent lighting while it is not present in the majority of available LED systems, if there is a broken bulb this is another safety hazard to consider, especially with children, pets, or any type of foot traffic in your growing area.

One extra consideration: HPS, Metal Halide, and even Fluorescent bulbs give off a significant amount of heat. If you are not sure you have the proper counteractive measures to mitigate this heat, not only will your plants suffer, but you may be creating a fire hazard.

10. Purpose
Take a moment to re-focus on the purpose of your grow light plans and needs now that you have read most of this article.

For a new comer, it can be tempting to buy a more complex system then necessary. One of the misconceptions about grow lighting is how little you really need to get a basic start.

Starting with a modest light set up, and making sure you have all other non-lighting aspects covered is one of the safest approaches.

With that in mind, here are some products to help you cheaply and quickly get started: Dual chip LED Grow Lights 10W SMD LED Grow Lights Lens LED Grow Lights

11. Miscellaneous Helpful Notes on grow lights
We will update this list and add on tips in the future:  more information please visit our website: ledgrowlight.co.nz

- fundamentally, all grow lights are replicating the sun. however grow lights are not as powerful as the sun, plan to run grow lights for 12-18 hours per day. Timers can help you manage this cycle.