What's the plan man?

[thestandard]

Very nice! That's the way to do it!

As far as getting that 400w HPS 12inches from the tops of the plants, good luck man. My 175w has to sit about 16-20inches from the tops of the plants. Seriously, i would sacrifice a little of the lumesn and ensure they dont get burned....

HID lamps just get soooo hot, its just their nature! If you have a fan blowing directly over the tops of the plants they will whither up and die as well, been there and done that, lol!

my MH is quite a bit cooler than my HPS, odd because all the FAQs say the opposite. however, 12-15" is completely managable imo as long as your airflow and ventilation is sufficient. I had the MH as close as 8" for quite a while when they were all the same height. Ventilation FTW, fresh Co2 as well as keepin temps down.


however, even tho i disagree with the fact that it 'needs' to be higher than 12.. I agree with what you say in a later post that raising it doesnt lose much lumens or power, I've had to raise lights because of 1 plant .. none of the others respond negatively

 

[That crazy vancouver guy]

in my experience, jj...

12" for 400 W, 18" for 1000W (MH) distance from plant

yes, you want intensity, but I mean... come on... look at the bulb at the plant's distance... u SEE a difference in a few inches difference in distance?... no... those are light rays... BUT there is a big difference in heat, isn't there???

 

[Cook_]

If you get burn you should def try splitting your lighting most people dont need 400watt hp all they need is 150watt hp or two... 400watt hp could probably do my walk in closet which is a 8'x6' walk in closet hope this helps

 

[Nova]

Put it this way.....i had my 1000w HPS Agrosun with an ultra-effecient ArgroMax bulb positioned about 5ft from the tops of the plants and still got burn......

I also have a 175w MH which i use for veg positioned bare minimum 18inches from the tops!
5x5
I got not stretching, very bushy, healthy from all grows. My only downfall was puttin up with power outages and the blasts doing growth spurts to reach the light.

I really dont care what anybody else says, 20inches is minimum i would to rpmote healthy unstretched producticivity, any closer and you might as well go LED or Cfl/Wfl route.

My grow area was 5ftx7ftx12ft and that darn HPS still got the grow room to 100+ temps even with adequate venting.....even though only 5x5x12 was utulized!

Take advise man, start high and move down slow! Remember all the new growth is on the top of the plant, untill you pinch or top, that plant will grow.....If it reaches the light and burns, it goes into a....repair....mode, which stunts overall growth! You dont want that! Sacrifice overall lumens for safe growing practices!

Once you lower and notice the top of the highest plant getting even the slightest crispy raise it up atleast 7-9 inches. This is only a recommendation.

This adive only comes to you from some who has been there and knows the heat generation and light generation by a similar system! My 1000w was too much for my grow room, but i grew fantastic buds. I ended up choppin 2 wonderful plants because they turned hermie mid-fem.....my only account is because of the heat and light intensity.....

Nova

(Im done posting here, grow boy doesnt wanna take my adivce, his probs! Ive done all i can to teach and eduamacate my fellow grower on what i have experienced!)

 

[Nova]

I'm sure they did get burned with a 1000 watt Nova. I'm using a 400 watt hps system and my plant tops are never farther than 12 inches from the bulb itself. I have two 9 inch fans blowing on the lights and plant tops and I have never had any problems with burning my plant tops. If I could upload some good pictures without having to crop the heck out of them, I would show you. 12 to 14 inches is the norm for a 400 watt hps or mh though. Take care and be safe.

I whole heartedly disagree with that!.....12inch from a MH/HPS is way too close....its too hot and too much heat and light intensity will promote hermie!

Keep in mind, we are all trying to reach the sun's potential. Its the frickin sun, unless someone comes up with fission in a can, good luck!

All you can do is do your best with what ya got. Maybe your system was able to get that close, but i spent a crap load of money buying the best, the best magnetic ballast and the best lamp, with the overall best hood. You look at my grow room, it was more than adequate for the design. You may get your HPS within 12inch, but that may because of ineffeciency of the bulb, how many hours have been put on the bulb? Who knows!

All i am saying, is play the safe and smart route, start high and lower later, it wont hurt really....It only takes 1-2 days to see if the plants are liking the light height! Beware, shortly after lowering it to the desired height, you may just have to raise to accomodate new growth!

Again, this just grows down to safe growing practices! Grow at a safe height, and leave a lil room extra for growth!

Nova

 

[Joseph James]

High intensity discharge lamps are bright-very bright. Growers who properly manage this intense brightness harvest more weed per watt. Intensity is the magnitude of light energyper unitof area. It is greatest near the bulb and diminishesrapidly as it moves away.

For example, plants that are two feet from a lamp receive one-fourth the amount of light received by plants one foot away. An HID that emits 100,000 lumens produces a paltry 25,000 lumens two feet away. A 1000 watt HID that emits 100,000 initial lumens yields 11,111 lumens three feet away. Couple this meager sum with a poorly designed reflective hood, and beautiful buds suffer big time! The closer marijuana is to a light source, the more PAR watts it receives and the better it grows, ( heres the catch ) as long as it is not so close that the heat from the lamp burns foliage.

amen

Its also says to hang a 400 watt HID 12 to 24 inches above plants.

I'm sure these words come with experience.

Why is your story so different NOVA?

Maybe it is not always as it reads in a book :holysheep:



Thank you guys for all the responses
​

 

[Cook_]

Tempered glass always helps to like pyrex

 

[Flyinghigh]

Ok I read everyone reply about how far the 400 watt light should be and when I put my plants back under CFL's ( Which there Happy Now) The Hps is to Hot for my Closet and I had LOTS of wind moving and my doors were open and the HPS Still Burned my Plants.

So next winter I will do another 2 grow and get a Softer HPS that not so bright in there and maybe I'll try a 250 watt..

Ok I have this light chart and hope this will Help...

 

[Cook_]

Im deff getting a 150hps this summer after looking at that chart ima have a mammoth