MH + HPS or Time Change??

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bump1987

Active Member
I'm having terrible troubles with the reliability of my MH bulb and hoping given information from this thread I can return it and only run HPS.

Obviously the bulbs are different parts of the color spectrum but I have seen multiple threads here that only run HPS and seemingly have good yields. This leads me to believe while lighting is important, its more the amount of light you have on hand that is important not so much the color?

Does the time change from 18/6 to 12/12 make a change well enough to trigger flowering even though lighting doesn't change? Do plants of multiple types veg under HPS equally? I know most of you grow bud but I am unable to do so at the moment so I am going for tomatoes and peppers to begin.

Whats the deal, and why? If you don't mind, of course.
 
woodydude

woodydude

Active Member
The time change is the only thing needed to trigger flowering. 18./6 is wasting 1/3 of your potential veg time, go 24/0. When changed to 12/12 or 14/10 this tells the plant autumn is coming and it is time to flower. You can veg under hps but get a dual spectrum bulb such as a Sunmaster. For the best veg results, get a T5HO light, they produce tight internode growth and yes, I have used them for tomatoes. Despite what you may think, spectrum is important, not just the quantity of light. This is why T5's and MH work so well, they are designed to work in the blue (6,500k) range. Flowering needs the red/orange spectrum (2,500k) range. For the best results, T5 for veg, HPS for flower and if you can, a 10,000k bulb for the last week, alternatively raise your light by 6" for the last week to increase resin production. Peace W
 
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bump1987

Active Member
Thanks for the tips Woody, i'll go ahead and ask for a replacement so that I can in fact run both blue and red spectrums in my growing. I'd rather not buy anymore bulbs until needed. 400 watts should do fairly well on 3 plants in an 18 gallon tub for now until the move to Denver. Then....it's on!
 
SimplySmoked

SimplySmoked

Well-Known Member
Everyone here has their opinion of what works and what doesn't, also which lamp is best for what. In all honesty they all work. My opinion is to keep with 18/6 so your plant has rest, maybe even 16/8, because thats the way god made them too, and scientifically how, plants work. I'd also recommend either a dual arc bulb or a MH conversion that run off hps ballasts. When you knock it back to 12/12, just shave an hour every few days until you get to 12/12. These are things that I do, that I like, for my grows. You'll get lots of practice though trying to figure out what you like, and what works best for you. Trial and error is the best teacher!
 
Robert Paulson

Robert Paulson

Active Member
SimplySmoked said:
Everyone here has their opinion of what works and what doesn't, also which lamp is best for what. In all honesty they all work. My opinion is to keep with 18/6 so your plant has rest, maybe even 16/8, because thats the way god made them too, and scientifically how, plants work. I'd also recommend either a dual arc bulb or a MH conversion that run off hps ballasts. When you knock it back to 12/12, just shave an hour every few days until you get to 12/12. These are things that I do, that I like, for my grows. You'll get lots of practice though trying to figure out what you like, and what works best for you. Trial and error is the best teacher!
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or you can throw 'em in a couple days dark and the plant will flower faster, rather than extending the transition period out for as long as possible.
 
ataxia

ataxia

Well-Known Member
just chiming in to say .... although i'm not a VERY experienced grower. I've witnessed the difference in light spectrums from MH to HPS although ...i was having a problem with my HPS and had to run MH during flowering.
Needless to say ... my yield was affected by a decrease of at least 1/3 or more.
i must also mention that the plant had recieved more light ( flowered alone as opposed to my current 4-5 plant flowering setup)

I also agree with the poster who suggested T5's. They are perfect for veg. IMO
 
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bump1987

Active Member
Robert Paulson said:
What problems are you having with your MH bulb? Are you running a digital ballast? if so what kind?
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It is not a digital ballast...i'm learning I should have slurged on one. I will later.

When the timer switches on for power to the bulb the MH arcs but doesn't ignite. It's like the gases have escaped the inner bulb, but at random it does ignite. I let it try to ignite for about an hour a couple mornings ago and it wouldnt. Well it hit midnight so I plugged back in (lights off at midnight) so it would trigger it at 6am and it would try once more. Well, it ignited and I had light. This being the case I left to visit my grandma a few hours away as it's only a test run as of now. No real plants that i'm worried about; they are germing anyways. Well, I got back and low and behold it's no longer ignited and only arcing the blue arc that it does when charging up.

The HPS bulb is running perfectly. It's not the ballast, it's not the timer, I have no idea what it is unless the bulb is just junk.
 
Robert Paulson

Robert Paulson

Active Member
bump1987 said:
It is not a digital ballast...i'm learning I should have slurged on one. I will later.

When the timer switches on for power to the bulb the MH arcs but doesn't ignite. It's like the gases have escaped the inner bulb, but at random it does ignite. I let it try to ignite for about an hour a couple mornings ago and it wouldnt. Well it hit midnight so I plugged back in (lights off at midnight) so it would trigger it at 6am and it would try once more. Well, it ignited and I had light. This being the case I left to visit my grandma a few hours away as it's only a test run as of now. No real plants that i'm worried about; they are germing anyways. Well, I got back and low and behold it's no longer ignited and only arcing the blue arc that it does when charging up.

The HPS bulb is running perfectly. It's not the ballast, it's not the timer, I have no idea what it is unless the bulb is just junk.
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Probably a junk bulb. I had an Eiko that was like that. I will only buy Ushio bulbs anymore. I've never had a problem with them firing and I run conversion bulbs too.
 
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