Earlier, I mentioned that I contacted the manufacturer of my 23W 2700k CFL lights. The specific model is CF23EL by sylvania. Here is the graph they supplied me with. I put it over the photosynthetic action spectrum graph to get a better idea.
As you can see in your example, the blue spectrum is actually better than the red as far as plants go.
There are varying opinions on what's best, but in general MH is preferred for veg and HPS for flower. The reason you're confused is because this thread is mainly about CFL or fluoro tubes as the light source, not MH or HPS. The spectra of MH is much different from cool white CFLs, and the same goes for HPS vs warm colored CFLs. If you want my opinion though, if you have a dual bulb hood, the combo of HPS with MH will be superior to dual MH for veg. You could do MHx2 or MH+HPS for veg and HPSx2 or MH+HPS for flower. Either way you go you should get really good results.
Excellent, thanks for the info.. I belive I will use the mix of MH+HPS for both cycles... Now this brings me to one more question? should I change the position of each bulb from time to time the hoods are about 2 feet apart and the spread from each 1 is quite wide and does definitely cover the 4 plants under them??
Not necessary, but it wouldn't hurt anything if you want to do it. Personally I'd just leave them in the same hoods the whole time just to test the difference between MH and HPS on flowering. The buds on both extreme sides of your grow area will be getting mostly light from one or the other of the bulbs since they aren't in the same hood. You can compare those at the end of the grow as well as the ones that got equal spectra from both and make your own decisions about what to do on the following grow.
sounds like the way to go thanks for the help and ill try to keep everyone posted on how it goes and what my opinion is in the end thanks again
Only if one doesn't take the time and effort to understand the how and why. Stereotypical stoners are 'supposed to' question authority, but then frequently act like parrots. All of the lighting knowlege I am passing on here was self-learned because many ideas passed off as truths did not make sense to me and so I did tons of research until I did understand. Reading grow logs and such is only a starting point and is not real research into plant physiology. One can grow awesome herb without fully knowing what is going on.
True, but without truly understanding, you only have two methods: 1. Copy exactly what someone else has done to get 1 GPW. Nothing wrong with that. 2. Blindly grope in the dark and hope you stumble on a technique. This may also work, but is a long round about path. Even worse than lighting, there is a huge mess of information out there regarding nutrients. I am currently using very cheap dry two-part nutes with nothing else. Are my plants optimized? I doubt it. But they are always healthy and I never burn them or have deficiencies, discoloring or leaf problems like so many growers that throw every miracle potion at their plants and wonder why they are sick and their wallet is empty. As electricity and nutrients are the most expensive regular costs, I thinks there is a huge area for improvement here. Every formula has a different ratio and there are hundreds of magical potions out there. This cannot be sorted out merely by reasearch though. Much coordinated trial and error needs to be done to cut throught the marketing hype.
That's because of grower knowledge though, not directly related to the nutrients. Beginner growers overfeed all the time. Or they have PH issues that cause lockout, but they think it's underfeeding so they feed more and make even bigger problems. People don't realize that the recommendations on the bottle are always skewed towards the high end. Why not? If you use them up faster you have to buy more sooner. Cheap nutes can do very well, and so can expensive ones, but the main factors as to how well your crop comes out are just grower skill and genetics.
True, but I have seen advanced growers with a whole pharmacopia of additives still doing damage. My whole point is that as much as possible we need to know why we are doing certain things if we want to go further than those cultivators who came before us.
A big part of the lighting confusion imo is the marketers of grow lights. I see the common misconceptions perpetuated all the time by manufacturers and retailers, it's easy to see why they stick around for so long. If weed were totally legal there would be a lot more real scientific studies done on it, but as it is now a lot of what we know requires us to experiment ourselves because the research just hasn't been done yet. Specifically on cannabis I mean. Most of it has been done, however, on other species of plants.
As good as my CFL bubble bucket was, I have easily surpassed it by using 4, 5, and 6w narrow angle E27 LED spotlights. I did another thread on this somewhere here. I can duplicate the same results I got with CFLs using LEDs of about 1/3 the wattage. And while I still use the bubble bucket because it was already set up, other growers can use these in an open frame as the 30 degree angle already contains the light. These are the future of vegging for sure - and possibly even flowering.
I too have done this cfl bucket thing, and had great results, and I want those results to continue, although my grow room is crowded for the moment, I'm considering a trial upgrade to this, using a bucket twice as big, and 3 cfl's 2 blue one red, diametrically opposite each other, will run tests, but may incorporate a small video card fan, note: easy enough to drill a few holes at the base and top to improve venting peace "V"
Right on the money, last time I checked my plants only understood the seasons and evolved for thousands of years experienceing seasons.
The sun is red in the morning and at sunset due to atmoshperic filtering of blue light. At no time is more red light added, but blue and green are dimished at the beginning and end of the day. The fall sun is not red at midday, only during sunrise and sunset. Please stop miseducating people here on things you have no knowledge of. Prove me wrorg and I will publicly apologize and delete my account. Of course, you will not be able to do such a thing.
Right... So when the sun is lower in the Sky much like the sunset, and alot like the land of the midnight sun the artic where it is Morning and evening for 3 months of the year. your saying that there is no shift in the light reaching the plants closer to the arctic circle. You would most definately be wrong, the one sun you said in your previous post is a no brainer, alot is filtered out by the angle of the sun through the atmosphere. Here is lotsa scholarly reading for you from really smart people who measure these things and actually know what they are talking about. No need to apologise or cancel your account. PAR Project So if you care to read go to the above link I think the graph puts it in terms better understood, You can see the obvious drop in PAR as the Sun drops lower in the sky every September. And then peaks in the summer in between. So as you will see the scientific proof you so desire, I still havent seen you source any of your material? Anyhow Enjoy
The color in the spring is the same as the color in the fall. Do growers use HPS then? No. There is less light in the fall than in the sumnmer. Do growers decrease light? No. Daily spectral shift is many magnitudes beyond seasonal spectral shift. Do we use HPS in the morning and MH at noon? No. So there is no mimicking of the light shifts and red light is not increased in the fall. Any angle of the sun filters some light out, but that has nothing to do with switching from HPS to MH. One can grow a perfectly fine crop all the way through with a single light source such as CMH or LED because no color shift is necessary.