Grow Lighting: LED vs. HPS
When it comes to growing cannabis, HPS lighting has been the stable workhorse for cultivators across the globe. However, there is an increasing trend of LED lights emerging, and the LED grow light industry is developing rapidly in both size and quality. So, we thought we would take a look at the two, and assess the pros and cons of each.
Log onto any cannabis growing forum, and you will easily find a heated debate about which is better: HPS or LED lighting. Look back at posts from a couple of years ago, and HPS was the clear winner. Sure LEDs could get results, but for the higher initial cost, they were just not good enough to unseat the HPS light from its throne. However, as the years have gone by, LED grow lights have come on in leaps and bounds in terms of technology and quality, and have substantially dropped in price. This has led to the arguments against them growing weaker and weaker. However, the debate still rages on, as those who have HPS in their blood are happy sticking with a tried and tested method, and more experimental growers sing the praises of their new fancy LED setups.
For the purpose of this comparison, we want to leave ingrained lighting habits behind, and look at both options with a fresh set of eyes – hopefully giving a decent and unbiased comparison.
High Pressure Sodium lights, or HPS for short, have been traditionally seen as the best of the best when it comes to grow room lighting. These lighting systems tend to have a wattage range of 75-4,000 watts, have ideal CCT levels for cannabis, and produce a hefty amount of lumens. They also come in all shapes and sizes, making them quite a versatile option.
The Pros of HPS Lighting
- Generally, HPS bulbs tend to encourage much more vigorous flowering resulting in larger yields.
- HPS lighting systems are much cheaper to initially buy than LED systems.
- HPS lights are standardised, making them easy to understand and know what you are getting.
- They are powerful – there is no question whether your plants are getting good quality light.
The Cons of HPS Lighting
- Although cheaper to buy than LED lights, HPS lights are power hungry and have a high running cost, especially when you have multiple 1000w+ bulbs.
- HPS lights generate a lot of heat, making adequate cooling ventilation a must. This heat can also be impractical for very small or micro grows.
- They often require a separate ballast and reflector to operate.
- They have a shorter shelf life than LEDs.
LED lights are relatively new to the cannabis growing scene, and had a pretty shaky start. They appeared with promises of increased yields, better growth, and higher potency, but for many, failed to deliver – especially where cheaper LED lights were concerned. This is why so many HPS growers remain sceptical of LED grow lights, because if something sounds too good to be true, it often is. However, since their emergence, LED lights have come a long way, and are now able to hold their own against HPS lighting. The real problem that persists is the massive range of LED lights available. They are not standardised in the same way the HPS lights are, and thus can vary hugely in quality brand to brand. Once again, if an LED light is cheap and promising the world, it is probably too good to be true. It is the tried and test brands, that often come with a high price tag, that really work wonders.
The Pros of LED lighting
- High quality LED lights are now able to produce the same light quality/intensity as HPS lighting.
- LED lights produce minimal heat – to the point where it doesn’t even need to be factored into ventilation.
- They are very energy efficient, and do not require the insane amounts of electricity that HPS lights do – saving on bills and fending off suspicion.
- LED lights have a very long lifespan, usually ranging from 50,000-100,000 hours.
- Many growers believe that LED lights produce better quality bud during the flowering phase, increasing potency.
- LED light units tend to be smaller, and don’t require a ballast or reflector, saving on space.
The Cons of LED Lighting
- LED lights can be extremely expensive to initially buy, especially compared to their HPS counter parts.
- There is not really any kind of standardisation in the LED grow light market
- As such, cheaper lights often suffer in quality, producing less than expected results and giving LEDs a bad name.
- The fact that LED lights produce minimal heat can actually be a disadvantage in cooler areas of the world, where the lighting is relied on to maintain a stable temperature.
- Whilst the quality of the bud may be better, LED lights generally produce less in terms of quantity.
As you can see, each type of lighting has its own benefits and drawbacks. The quality debate is becoming less and less relevant, so it is really going to come down to what you need from your lights. Generally speaking, simply because of the initial costs involved, HPS lights are probably going to be better suited to the hobby grower tending a couple of plants. However, if money is not as much of an issue, and you are looking for long term efficiency, then LEDs may be the way forward. Also, if you are growing in a very confined space where heat is going to be an issue, then LEDs are going to take the worry of a fire hazard off your mind.
If you really want to get the most from your cannabis, and have the room to do so, there is a growing number of cultivators who use both HPS and LEDs in tandem, bringing together the advantages of both, and cancelling out many of the disadvantages of simply selecting one type of light. Of course, this is even more expensive, and probably not that practical for a lot of smaller grow tents, but the option is there.
Either way, whilst HPS lights may not have lost their throne, they should probably scooch over a little bit, as there is no clear winner any more. At the time of writing, we find both high quality HPS and high quality LED lights to be equal having weighed up their current pros and cons. However, HPS lights have reached their peak in term of developments, where LEDs are only really getting started. Who knows what the future may hold.