ok peeps, a single CFL against a single hps, each being 250watts, which would give off the most heat? and which would give off the most usable light? all facts and opinions welcome if anyone has done a side by side grow with these I would love to hear from you the area to light up would be 1.5x2ft. and 4ft tall
HPS=29000 initial lumens CFL-18000 initial lumens (about the same as a 100w HPS) I'm pretty sure you have seen my 400 HPS in a 4' tall box. And NotSure's 250 HPS grow is awesome, 5.9 zips out of a space like you are talking about.
what are zips? I have never heard of that expression? I didn't know about those lumen numbers. you can have plants about an inch from the CFL so you would get almost all those lumens, how close can you get a 250w hps?
250w cfls are $70+ and you would need two. One in 6500k for vegging and one in 2700k for flowering. For that price you can get a 400w HPS.
the cost to buy them is irrelevant to my application, but thanks anyway besides, in the UK a 250w CFL costs less than £30 delivered to your door, about £25 if your willing to pick it up
zip=ounce. My 400 HPS is in a diy cool tube and I can put plants 4" under it. HID lights are the best for growing pot. CFLs get the job done but they can't penetrate like the HIDs can.
I hear that all the time, and its true when you compare a common hps (600w) to a common CFL (125w) but I'm not interested in anything other than 250w because they are directly comparable. I want to compare 250w only, heat and the light output at a usable distance I'm not looking for grow advice, I have 9x 600w hps lamps here, I also have several 125w cfls. I'm just interested in the comparison, and to do that the wattage has to be the same otherwise it's not a fair comparison
I know. I don't have a 250w, so I can't speak to it. But what I do know is that my 400w is way hotter than a 250w would be. So If I can get my plants 4" from a 400 than there should be no problem jamming a 250w as close as you want. I did not realize that I was offering unsolicited advice, or offering advice at all for that matter. Just my $.02 but I will keep my pennies out of your thread dude. Good luck with your research.
Added a 250 hps to my CFL's, about 250W also. My box is small (3x3x4) and have a fan blowing directly under hps and another small one wherever is best. Have (2) 120mm pc fans for exhaust. It needs more exhaust really but with the door cracked it's ok. Gotta fix it for better airflow come next summer. peace HTH
i meant no offence mate, maybe i over reacted, it was between your comment and fluffykush's comment that gave me the impression that the conversation was started to slide to someone using a bigger lamp. im just wondering the difference between hps and cfl. im trying to get more detailed info. i could compare a 400w cfl and a 400hps but i would feel those two are less comparable. the hps would give out far more light, but of course far more heat too. getting your 400w within 4" is impressive, but with the extra expenditure and complications its even harder to compare the two im comparing 250w lamps because they are both common and many people use them. i figure the hps would give off more heat, not that the cfl runs completely cool either. the hps obviously gives off more light but because you can get plants within an inch of the cfl you get all the initial lumens, with the HPS you would need "x" amount of distance equalling less % light to the plants. im wondering what the difference this amount would be and also the question of "does cfl have a larger usable % of its own light than HPS"? i know HPS emits light that the plant cannot see, i dont think this is true about the florescent, or at least not as much as the hps. so all these things start to balance them out somewhat
ok, but im going to try anyway ill tell you how this all started... whenever someone asks me about light sizes and types that are best suited to them and their grow area i often reply with "cfls are great up until you hit 250w and then you may aswell go HPS". im started to doubt i have enough detailed information to hand out this advise so im looking for more info, i dont actually have any 250watt hps or cfls so i dont know how much heat either gives off. i can take an estimate because i regularly use 400w and 600w hps as well as 125w cfls, but this is what forums are all about for me, sharing facts and opinions. its a shame these two often get mixed up though
xproject, about that table, i had no idea what foot-candles are so using an online calculator to convert it to lumens it has confused the hell out of me. according to the table and the calculator a 250w hps at 12inches gives 8754 foot-candles, which is 94227 lumens/metre, this cant be right surely? further research on the 250w cfl im getting quotes of anywhere between 9000 lumens right up to 20,000 lumens from different suppliers. im starting to think this is impossible to work out
here's the way i have this question worked out in my head: cfl's have good efficiency giving off good lumens per watt, resulting in a smaller amount of heat being created. however, the amount of light created per bulb is much smaller, which means you have to pack more bulbs (or bigger bulbs) into your grow space, and keep them closer to your canopy in order to keep them within an efficient distance from your plants. HID lights beat out cfl's with sheer brute force. they aren't quite as energy efficient, which means they create much more heat, but they pack such a huge punch and take so much less space that they've won the growing market. they're so powerful you can keep them quite a bit further from your canopy and still have at least the same amount of lumens hitting your buds as the cfl's did. but what's nice about this is that keeping the light higher up means you can light a much wider space. this is the reason why lots of people refuse to switch to LED. they're incredibly energy efficient, and you can choose *exactly* what spectrum light is shot on your plants, but you have to keep them so close to the canopy (nearly touching is best) that you have to get a big panel to cover a big area. so to answer your original question, watt for watt the HID will give both the most usable light and the most heat. if anyone has any information i didn't provide, whether it proves me wrong or right, i'd love to read about it. i've been eyeballing the exact same question for a while now and this is what i could come up with.
Ran same strains, both in Power growers in a 4x2x5 cab, scrogged/topped with FF full line of nutes. Grow1 used a single 400w MH for veg and 400w HPS for Flower - both 6-8 inches from canopy. Grow2 I used 432w of T5 lights (4 dual 48in). I used Veg bulbs for veg and Flower bulbs for flowering. MH/HPS had more compact nodes and better overall color. Growth was slightly faster in Veg, but more stretch when switched to flowering (about 3-4 inches more). T5 grow was better than expected. Node spacing wasnt as tight, but I didnt get as much stretch. coloring was decent, but not as bright green as HPS, seemed to be slightly darker green. Heat was about 3 degrees cooler (71 ambient, 80 with HPS, 77 with T5). I also couldnt push as much nutes to the t5. I think i maxed out at 1100ppm with T5, were as I could get them up to 1600ppm with the HPS MH/HPS yeilded 8.5oz. T5 yeilded 5.1oz. MH/HPS had slightly more crystals and a better high. Taste was about the same. Now i normally use a single 400w MH/HPS with 216w of T5 (mixed bulbs the entire time). I use the other two T5 hoods for my veg cab.
I did cfls for my first grow and veg of my current, and ~5 weeks into flower second grow with a 250w MH and the buds are already much denser than my first grow. I LST'd to try to get the most out of each plant and if you aren't doing a scrog it can be hard to get all the lights in the perfect spots so that there is both room for the plants to grow, and also room for them to not burn themselves. Even with the cfls within 3" from leaves and everything the buds were still fluffy and light. I did also have a fungus gnat problem, powdery mildew, and pH stress... twas my first grow. I'm sure that an experienced grower could pull a nice yield off of cfls but it's much easier and less chance of problems with HID lighting. Sincerely a CFL and HID grower.
the bit that really stood out for me there was the fluorescents had the grow area just 3'F cooler? was it the same grow area? were the two grows going on at the same time in the same room? were there any ventilation differences?