Lighting

As another year draws to a close, now is a good time to reflect on how our gardens have performed over the last 12 months. How have they developed and what – if anything – did we learn? As, I’m sure, many of you will be winding down to enjoy the festive period, take a few minutes out from devouring masses of food and – hopefully – your recently harvested green and start planning for the New Year.

As another year draws to a close, now is a good time to reflect on how our gardens have performed over the last 12 months. How have they developed and what – if anything – did we learn? As, I’m sure, many of you will be winding down to enjoy the festive period, take a few minutes out from devouring masses of food and – hopefully – your recently harvested green and start planning for the New Year.

Rather than bash together an article on preparing a grow room for the New Year, I thought it might be more helpful to focus on a few techniques and products that’ll help you go that extra mile in pushing your room to the limits. A few suggestions for those of you that don’t mind experimenting and changing things up a little to try and set a new personal best for your room.

Before we get into it, it’s worth noting that these techniques are for those of you who have your rooms pretty much dialled in. That is, you’ve been running things over 12 months and get consistent results each time, regardless of what the weather’s like outside. It doesn’t necessarily mean that any of these products or techniques are difficult or advanced, more that if your environment isn’t right in the first place the techniques probably won’t get you the results you’re looking for. Or, in certain cases, could do more harm than good. If you’re happy enough with your set up and have tweaked it over the last few grows to the extent that your plants aren’t stressed to fuck when the outside temperatures alter by a few degrees, then read on…!

This issue we’ll start with lighting;

Probably the most important factor in your growing environment, since without it your plants won’t photosynthesise and grow, there are plenty are lighting tweaks that will increase the performance and output of your room. 

Bulb – that £65 light kit that you bought to get you started may have been great value at the time, but it isn’t going to cut the mustard if you’re attempting to push your plants to their limits. Once you’ve had a few grows out of it then it’s time to upgrade your bulb – at the very least – and then take a look at doing the same with your reflector. We’ll presume that you selected a branded ballast and it’ll do another 6 months or so without melting through the floor! 

Choose a decent branded bulb like an Osram, Sylvania or push the boat out and get a Phillips. It’ll cost more, but the output will be significantly higher than a budget lamp and you’ll notice the difference in plant development and, ultimately, yield. For best results, try a two bulb technique. Metal halide for vegetative growth – keeps internodes short and promotes lateral growth – and a HPS in the red spectrum or a dual spectrum HPS for the flowering phase. I know lots of growers that favour using a dual spec bulb in flowering as they like to keep a little bit of blue light in the spectrum to reduce stretching. Some believe that a bit of blue light also improves the quality of the end product.

Ballast - Now the best bulb in the world won’t help your plants grow any better if it doesn’t receive the right amount of power. This where your ballast comes into play. Joking aside, if you did purchase a cheap-arse budget ballast there’s the possibility that it may be under powering your bulb and this will reduce efficiency. Under or overpowering the bulb will still cause the gases contained in it to burn and produce light, but the output will differ from that which the manufacturer designed them for. In layman’s terms, you won’t be getting the output that you paid for. The answer? Beg, borrow or steal a plug in energy meter, plug your ballast into it and fire it up. Check the wattage that your ballast is drawing and remember that magnetic ballasts draw around 10% more wattage than the bulb requires, this is to make up for the energy they lose in heat. So, your 600watt magnetic ballast should be drawing a minimum of 660watts. Are you getting what you thought? If not, it’s time for an upgrade… don’t cheap it out this time, you get what you pay for.

Reflector – A great quality bulb and ballast combo can be rendered totally impotent if the reflector isn’t up to the task. Even the cheapest reflectors out there still do a sterling job of reflecting and distributing light evenly over your crop, so there’s no excuse not to replace them once a year. Dust particles build up on the surfaces of metal reflectors and they’re difficult to clean off without scratching, which will affect the light intensity and distribution. Reflectors degrade quickly and this will affect the performance of your room.

Get a group of seasoned growers in a room together and ask them what the best reflector in the world is and you’ll probably get a different answer off each of them. There’s not enough word count left in this article to describe the different varieties of reflector on the market and their various pros and cons so we’ll save that for a later issue. But, broadly speaking;

Wing-style reflectors can be placed closer to the crop as their two open ends allow for heat to escape, although light intensity is lost along with the heat.

Closed ended reflectors provide maximum light intensity as the majority of light emitted from the bulb is reflected down towards the plants, as is the heat, so these can’t be placed as close to the canopy. Some growers swear by parabolic shades which offer the best of both worlds; a closed sided design complete with a wide spread, allowing then to be placed closer to the canopy.

Air cooled reflectors allow for multiple lights to be used in a grow space without negatively affecting the room temperature, they can also be placed close to the plant canopy. However, up to 5% of light intensity can be lost through the glass screen on the reflector and constant air flow passing over the bulb can reduce its temperature which can affect the quality of its light output. It’s swings and roundabouts. Do your research, pick the design that suits your room the best and make sure you keep it properly cleaned and maintained. 

New lighting technology – If you do decide that it’s time for a complete upgrade on your lighting and you fancy splashing the cash on something that’s a bit special, there’s some new technology out there that can make a serious difference to your yield. From speaking to many UK retailers, it’s clear that 400v fixtures are now the preferred choice of the connoisseur grower. These HPS lights step your voltage up from 240v to 400v and power a high frequency bulb which emits around 8% more usable light than a regular 240v fixture. They’re usually an integrated fixture with the ballast mounted directly onto the back of the reflector and bulb holder, doing away with meters of trailing leads thus seriously reducing the risk of EMI (electromagnetic interference) playing havoc with your neighbours wifi! 

The leading brands of 400v lighting units also produce their own digital controllers which completely do away with mechanical contactors and instead keep your ballasts running on standby during the off period (just like your tv at home) this means that there is no power surge when the lights are turned on. Add a temperature sensor to the controller and it’ll automatically dim your lights when your room gets too hot. Some brands even go a step further and integrate measurements and control for humidity, CO2 and plant vapour pressure deficit. Mesmerising shit! 

New lighting kit that utilises LED or LEP bulbs are featured in this fine publication fairly frequently, but another trick piece of lighting kit well worth checking out is Ceramic Discharge Metal Halide or CDM. The easiest way to describe it is that it offers a light spectrum that is close to plasma lighting (which is as close to natural light as you can get) with the intensity of 400v HPS lighting. It’s incredibly efficient, putting out 1.9 micromole (umol) per watt of electricity, in other words that’s extremely high PAR levels. These 315watt fittings can be used as a sole light source or added amongst HPS fixtures to enhance yield and quality. Oh, and Phillips make the bulbs, so you know you’re dealing with quality.

Now that you’re lighting is sorted, it’s time to play around with a few techniques;

Gas Lantern Routine (GLR) – This one was brought to my attention earlier in the year by a mate who runs a shop up North. I’d never heard of it before but a bit of online research brought up plenty of mentions on the usual forums. It’s basically a lighting schedule for the vegetative phase that promises to supercharge your plants with flowering hormones as well as saving almost 50% on your electricity.

For decades now indoor growers have stood by the tried and tested 18/6 lighting schedule for the vegetative period, reducing down to 12/12 for the flowering period. The schedule loosely follows natural lighting patterns where a reduction in daylight hours (after the summer solstice) indicates to the plant that Autumn is on its way and it’s time to reproduce and generate flowers. The GLR is based around the theory that plants only require 13 hours of light to remain in the vegetative phase and that nowhere in nature would a plant receive 18 hours of continuous light – not even equatorial strains. In fact, 18 hours of light actually stresses the plant.

The GLR lighting schedule involves 12 hours of light, 5.5 hours of darkness, a single hour of light and finally another 5.5 hours of darkness. Basically a 12/12 schedule with 1 hour of light inserted into the middle of the dark period to prevent the plants from flowering. The idea is that the prolonged dark periods allow the plant to rest and develop healthier roots, stems and vegetation. The plants are charged with flowering hormones but the single hour of light prevents the plant from flowering, when that hour is removed they explode.

Converts to the GLR absolutely swear by it and state that their plants grow much faster in veg, stretch less when they enter the flowering cycle, show flowering sites far earlier and are generally healthier and less stressed as there isn’t a huge reduction in lighting from veg to flower.

Many users of the GLR also follow our next technique…

Diminishing Light Schedule (DLS) – In nature, the amount of daylight decreases towards the end of the growing season, forcing the plant to produce more flowering hormones and divert more energy into flower production. Rather than set your lighting schedule during the entire flowering period to 12/12 – which is basically the borderline number of hours that will induce flowering – start at 11/13 (light/darkness) and increase the dark period by 30 minutes every two weeks. For example; 2 weeks at 11/13, 2 weeks at 10.5/13.5, 2 weeks at 10/14, 2 weeks at 9.5/14.5 final week at 9/15.

The additional hour of darkness (11/13) at the start of the DLS sends the plant a clear message that the time is right to flower whilst the diminishing light hours throughout the rest of the flowering period will force an increase in production as the plant realises that her end is nigh!

Growers that I spoke to that used the GLR and DLS techniques reported more flower sites, far greater resin production and, subsequently, more weight. Plus, a significant saving in electricity. 

Of all the new techniques that I’ve discovered this year, this is the one that I’ll be taking a punt on… who’s with me?

Happy growing!