LED VS HPS 2012
It all started with a bet.
I was researching LED grow lights for an article on another site. In order to justify the higher production costs of some of these units retailers bamboozle a poor girly with science, and I was forced to draw hard on old “A” Levels, Campo’s 2 years of college horticulture and a fast-track online learning curve in order to make sense of some of the claims made and translate them into hopefully understandable english.
(you can read a copy of the article here)
“You know” I said .. “I think we ought to try these”. We have heat issues where we live which pretty much rule out anything but outdoor grown weed for half the year. “Hmmm” was the reluctant reply. The issue being of course, not simply the higher initial cost, but proof of the efficacy of these lights to grow good bud. After all forum posts tend to be either by newbies – and who knows what problems they might bring to bear on any grow?, or by experienced growers – and who knows how much they’d have got if they’d stuck with good ol HPS?
The only way to find out if these LED grow lights actually perform like they claim was to pit one against an HPS system. Same plants, same environmentals, same grower. Reading around the forums, we decided to write to Fero-LED. They acknowledge what their lights are being used for and seemed interested in developing a good system. So we challenged them. “Fancy putting your money where your mouth is?” (or words to that effect). Surprisingly the reply was a typically Canadian “Awesome!” … and we were off, bets were on and we set out to answer the question:
Which is the best grow light for a closet grow?
Anyone who has looked into LED grow lights knows that for the small time personal grower, LEDs have all the advantages:
- low energy useage that won’t impact noticeably on your electricity bill
- long shelf life
- small compact unit – simply plug and play
- light and easy to adjust heights etc
- no heat issues needing to be resolved with additional equipment. A small bathroom sized extractor fan necessary for airflow, not something that sounds like jet aircraft are taking off nearby.
At first signs of sexing they were transplanted into larger pots in a coco-perlite mix and moved into their respective grow rooms. All plants were labelled (tippexed) directly on the pot so there could be no chance of mistake.
- The original Fero 357 (which only has a 120 watt draw) had been replaced by the new Fero4G 360 model (with a 256 watt draw). Plans had been to make the change earlier, so as to match like with like a bit more, but those nice men at customs had held up delivery.
- Plants were moving nicely into flowering stage, BUT we realised that there were within the group of 6 female plants 3 genotypes emerging. How much would these different genos impact on final result?
Can LED grow lights make good bud?
Well, despite being pretty much the same as they started flowering properly, after 30 days under the different light systems, there was beginning to be a noticeable difference:
and no, I’m not going to tell you which is which. Be reassured that pots themselves were marked and never muddled up.
Want to know the results of the LED / HID grow-down?
Well here’s a summary:
OK so the chart doesn’t scan in well (all the info is in the original posts anyway) .. so in case its too blurry to read, the final results are
LED – 193.2g
HID – 153.6g
which quite frankly is not what we were expecting at all.
When we went into this, I cannot emphasize enough that at best Campo thought the LEDs would produce comparable bud. Everything he had read on LEDs in articles, and as a super-mod, suggested that unless you were very experienced in their useage (and there are special techniques to growing with them) and combined them with all the gizmos (as most techno-LED growers seemed to) the results, certainly as regards flowering, weren’t all that.But as day by day passed and I remembered why my moniker is “Weed Widow” as I lost my other half to the joys of the grow room, a few things soon became apparent:
- bud development under the LED was more “solid” to the touch than that under the little 250 watt HPS, where quite frankly it still felt loose and airy. The main cola buds on the HPS ended as smaller buds after drying: under the LED they remained as one big bud.
- light penetration was greater with the LED: I tried to take photos of this, but aesthetically they don’t work very well (I can post them if anyone wants me to!): the small buds at the bottom of the plants were actually forming into useable bud rather than just popcorn.
- there was, we felt, a noticeable difference after we swapped the 3G 357 for the new 4G 360 model.
We know there are some flaws in this trial. Here’s a few pointers we think ought to be made clear.
- We don’t work for or have any professional relationship with FeroLED lights. However, from our experience using their lights and our emails with the company, we would definitely recommend them to anyone considering buying a grow light system. The lights are solidly built, work well and the customer service is excellent.
- As I said above, the aim of this particular test was to see whether or not LED lights really were worth considering for the small persy grower. Hence we pitched a small LED against a 250 watt HPS over just 4 plants. YES, there is the possibility that the trial would give different results if we put say a 600 against the 4G 900 (with a 645 watt draw).
- Genotype variance amoungst the MI5 seedlings was a disappointing factor that we hadn’t allowed enough for. Who can really say how much influence the 3 distinct types had upon the final result? Having said that one would expect the larger plants under the HPS (in one case twice the size) to produce much more bud than those under the LED.
- YES, some plants took longer to mature than others. The Cream Caramel under the LED, 1 of the LED MI5s and 1 of the HPS MI5s finished 9 days after the others. I don’t actually see that as much of a problem. Plants are ready when they are ready, not in accordance with a seed packet. And given that the LED Cream Caramel gave 66g dried weight against 36g for the same sized plant under the HPS, I think those extra 9 days were worth waiting for. Anyone who would do otherwise is quite frankly a fool in my book.
- Re the comment that LED-grown weed tastes different. Campo has been toking daily (give or take the odd day) for only 19 years so cannot claim to be an expert. “I can’t taste any difference” he says, “I have a joint and I get well stoned. I’m happy.” So we gave some to friends as testers, they couldn’t tell either. The only relevant comment was that one person felt his 4g bag was smaller than his mate’s. They’d both been weighed the same, one just looked less (denser heavier bud). He had the LED.
- whilst this was not a truly scientific grow it did aim to replicate fairly the growing conditions your average Joe Toker uses for a small personal grow. There were no high-tech extras. A diary was kept recording Campo’s observations throughout.
- Grams/watt doesnt work out super brilliant for either grow, and Campo was very concerned about this throughout. The problem was not enough plants for each grow space – there were quite a few gaps. This is a problem with growing autos in pots, you just don’t get that sea of green effect.