Full-spectrum all the way thru, or take mh out for flowering???

I have grown indoor for about three years now, and outdoor for the better part of 15 years. I currently have a very bushy, super-cropped Grandaddy Purp, a Purple Kush, and four hybrids growing beautifully in a 4'X2'X8' closet. It is very well ventilated, and I am in my last two weeks of veg. I am using one 400W MH and three 250W hps for full-spectrum benefits, which I have found to be excellent. However, I am toying with the idea of taking the mh out of service when I switch to 12/12 in a couple more weeks, and then putting it back in service for the last two weeks of flowering, while I flush with straight distilled water. Does anyone have any recommendations for or against this practice? I know it will help my temp to be a little lower, which is around 80 degrees F now, but I'm just not sure, and want to do what is best for my ladies. Any input would be greatly appreciated!

People have had success either way.
Some MH in flower is good in my opinion - it made for less stretch and tighter nodes in my grows.
I have mine switch on after the HPS and off before on a decreasing time scale to simulate less and less blue spectrum light as happens naturally during seasonal lighting changes.
using MH at the end can be good also for the little extra boost of UV that they produce (Cannabis makes THC as a UV Protectant)

I have a small test budroom I've been using this past year. I did some full spectrum intensity testing. This is for a sativa clone, plants do react differently.

But anyhow, the plants grew better with more light, right up to the overload limit. You will know if you reach that high.

And if the MH was used from day one the peak oil came sooner, not any more of it but the plant started making oil first when the MH was shining on it.
Mixing the two lights gave 5% bigger buds than MH alone, and they oil still came in earlier than HPS alone. Mixing them put more light to the plant, more light is always good.

Most for the electric costs and most, two different animals. Hence the conflict.

Awesome guys. I appreciate the input. I may just leave it in there. Stretch could and would be a problem for my setup if they got any taller than they already will when I switch to flowering in a couple weeks. I've lowered my buckets and tied down some of the taller kola stalks to allow for more horizontal growth instead of vertical growth. And I've also raised my lamps up almost as far as I can, and I'm holding steady. They are all very happy, healthy plants with a perfect "greenhouse burn", so I think either way I go, it will still end up a success. I am using absolutely every bit of space I have to it's fullest potential, and Lord knows, 1150W of full-spectrum in a 4X2X8 closet is more than enough light. So, with the worm castings, nitrogen-rich guano, and liquid seaweed I've used for veg, I've seen amazing results thusfar. And when I switch to a phosphate-rich guano via teas, and continue with the liquid seaweed and worm castings, I believe i will be a very happy farmer in a couple more months!

the fuller the spectrum the better results you will have. plants need red and blue for optimum growth and a little green and yellow too

http://jxb.oxfordjournals.org/content/61/11/3107.full

Awesome, I think I agree with the more lights, the bigger, and the better of a return I will be getting. Hell, I even threw in a 75W-equiv(as if itz gonna make any difference!) in with the 400W MH, and the three 250 HPS's, just to say I have over 1200 watts of sum dank-makin' lumens in there. Went ahead and gave em a little 0-10-0 bone meal to get em ready for the phosphorus in the bat dewdie that I had the hardest time finding. Hell, everyone has the nitrogen rich kind, but what's up with the phosphorus rich kind? I dunno...Ah, the "problems" associated with growin' killer medicine! I just can't wait until after T-giving, and hopefully just before Christmas, when this good boy'll have his stockin's full 'o righteous dankage!!! It does feel great to watch my bounty grow everyday, right before my eyes, knowing they're loving all the awesome organic nutes I'm giving 'em, and the awesum light I have 'em under, and all that jazz!

Ok well having more wattage and lumens does not mean better return. Most HID's put out a horrible spectrum. Companies are just recently starting to make better spectrum bulbs. What you want is a better fuller spectrum. .......Lumens by definition is visible light. Plants only absorb about 5 - 10% of visible light. Plants mostly absorb uv light and infrared light which HID's don't produce.

I recently switched from 1000w with a eye hortilux bulb to a T5 using aquarium coral reef bulbs that produce a much higher PAR. For half the wattage and having much better results. I did a side by side actually currently still doing. check my journal. Im going to shut off the 1k next week and sell it.

PAR is photsynthetically available radiation or Photosynthetically Active Radiation. Photon flux density (photons per second per square meter) within the visible wavelength range (usually 400 to 700 nm). It indicates the total energy available to plants for photosynthesis, and is thus a key parameter for biological and ecological studies. Thats what you want. so throw the term lumens out the window, it's irrelevant. my 1k is 10% PAR where my t5 is around 90 % PAR. closer to the sun which is or close to 100% PAR

read the article on the link in the post above.

for hid's the best bulbs I can find are the ushio super mh and hybrid dual core

http://www.ushio.com/products/horticulture/hiluxgro.htm

Good luck and happy growing

You are correct. And as a journeyman electrician for approx. 15 years, I am impressed. I agree. I use some nice $35 cfl's inside my trusty, ol' phototron for my clone/veg chamber and it does very well to keep my cuttings and sometimes new seedlings growing nicely until they get ready to be transplanted into the much larger, 5-gallon buckets over resovoirs in my main grow closet, but i do use top of the line lamps in my magnetic type ballasted hid lights. I am very interested in the new 1000W dual-spectrum lamps I see in H.T. that have a 400W MH and a 600W HPS all inside of the same lamp, which looks to be of the same size and basic shape of your norml 1K HPS lamps. I believe it is set up to withstand the acoustic resonance of the much higher frequency, I think around 20,000 Hz, of the newer digital ballasts, so one or two of those kits will most likely be my next lighting purchase. I have used just MH before, and the potency of what was, I believe, some feminized Lemon Skunk seeds a friend had ordered, was just not there. They looked, smelled, and tasted wonderfully, but that thc and resin production was just absent, so, it was a huge dissappointment. But it was one of those mistakes many "budding" growers have to make before they learn what is best for the plants, and why we give them what we give them, and when, and etc, and etc... But my next grow afer that one incl the 400W Mh and two 150W HPS, and things got better, and then I finally got some "extra" 250W HPS kits and lamps from a job I did, and they have been a staple along with my trusty 400W MH ever since, and the results have been mind-blowing. The proportion of 750W of spread out HPS red/yellow spectrum along with the blinding 400W white/blue MH spectrum works like magic in my closet. So, we will soon see how well it does with Grandaddy Purple, Purple Kush, and a few ind/sat hybrids I have this time around. Pics will be posted soon.