Cerebro

agreed, but i wouldn't be surprised to see a fair bit of stress in the plants if you throw them from low powered cfl's to 800-1000w HID, especially if temps are way different.
but, it should be fine if those HPS lights are right for your growspace.

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TheSalmon

has anyone ever used LED's in dual spectrum for aiding in the vegatative state while using a HPS light???

seaflo

I think Farmer has it; CFLs are great for vegging and have even used them through the entire grow. The trick is the amount of lumen; my experience is that you need approx. double the wattage of CFLs to equal HPS for flowering. The fact that doing this brings your power usage back closed to the HPS level. I currently run CFLs for all vegging, including seedlings, clones and the infirmary. I have never seen stress when switching from CFLs to HPS but you gotta keep your temps relatively constant; can't place the HPS near as close as the CFLs from the plant too. I have HIGH hopes for LEDs but the cost is prohibitive and their results have not thrilled me yet. CFLs are loaded with mercury and that ain't good. The real deal is gaining as much research and as much experience as possible. Growing, like life is a learning experience. Good luck.

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TheSalmon

is it blue light or red light that is needed for veg period??? I was at my local hardware store yesterday and they had some different colored lights with lots of lumens. And with LED's they aren't cost effective yet but what about supplementing your HPS during veg period that might be a good idea

MannyBoy

Thanks PG.

I just want to clarify one point. You mentioned that to get the lumens per square foot - one divides the lumens available by the total ft2 space. Simple enough. My question; say you have 10 ft2 physical space in the grow cabinet, but you are only occupying 2 ft2 with plants. It would be incorrect to divide the lumens by 2 ft2 (the actual occupied plant space)? In other words in this example, the 8 ft2 of unoccupied space sucks up the 80% of the lumens?

If so, I need to place dividers into my grow cab to cut down on the actual physical space.

One complicating factor for my situation, I will use a LED panel. The LED's are focused to throw most of the light down and a bit out. My panel is about 18" square, but when I hold the panel 3 feet above a surface like a table - it is kind of like a flashlight - you see a distinct spot of light about 3 feet in diameter.

MannyBoy

PeaceTurtle, please keep us updated on your LED grow.

What are the wattages of your LED lights? Do you know the proportion of blue to red (and possible orange) lights on your bars/panels?

I am soon starting my first grow. I will be using one 45 watt LED grow panel from seedling to harvest. The panel is about 70% red and 30% blue LED bulbs. I know my lack of experience in growing the good herb will contaminate the results of LED "experiment," but I am willing to try.

Lastly, I keep reading posters writing that LED panels are cost prohibitive. Maybe in the past. Now, a 45 watt panel like mine is less than $120 US dollars and there are many 90 watt UFO LED lights out there for less than $200 US. Add in the very relatively low cost of operation (my 45 watt LED is supposed to be equivalent to a 250 watt HID), plus heat reduction components (shields, exhaust fans) fixed cost and their electrical variable costs, plus now bulb replacement for years of continuous use - and it is not hard to see the upfront and downstream costs of a LED system is far less costly than a typical HID system.

Cerebro

you can choose to read the positives of led's, or the negatives
glass half full etc
i was a salesman, i didn't 'sell' the negatives of my products
the things that i'd say about led's are
currently most bulbs are only 1W, that's not very much
and doesnt throw light a long way
the intensity of led's is limited to directly below each bulb
the loss of intensity is dramatic, even a few cms from midline
so, if you want to grow something that's straight up and down then it could work
but it wont grow a very good christmas tree
led's only work if multidirectional, meaning more lights
meaning less advantage
or as supplimentary lighting
the costs need to keep coming down, or those 3W, 6W, 9W bulbs need to become mainstream before i'd recommend one over a HPS

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Kaminoan

Time to look again, Cerebro I am having outstanding success with 5-Spectrum LED's for veg & flower... I am running one 100W in a 4x4 veg tent and have taken plants from propagation to the flower tent. We are finding that we can lower the LED's during flower to less than a foot off the tops. The colas are going crazy with no threat of burn. I see the defining issue as this: 16 plants in a 4x4 would use 2 1000W HID's and I can achieve the same with 4 200W LED's. The 1000W bulbs are good for two crops and the LED's go 50,000 hours...