using metal halide during flowering

[keepleft]

hi ive got the luxury of dedicated HPS 1000 watt globes/ballasts and also MH 1000 watt globes ballasts.

 

traditionally, ive used the MH in veg then as soon as they go 12/12 i switch the globes and ballasts to HPS.

 

ive been told the following:

 

1. use Metal Halide lights until the start of your 3rd week of flowering to control your node lengths (hieght)

 

2. finishing with halides for the last week or so >icreases the density

 

3. HPS lighting is more absorbed by plants and gives a quicker growth rate but

at the expense of internodal stretching. If using HPS right through i would advise to clip out your centre lead stem to encourage lateral growth and a shorter structure. A good time to do this is after you 2nd week of veg or at

aprox 18-24inches high. If you strian still stretches Halides will be very

beneficial.

 

what are people's thoughts/experiences with using the MH for the first 2 wks of flower then switching to the HPS then switching back to the MH for the last week of flower. (PS. this would be without the use of PGR's).

[WantDaChronic]

from what i have read, you'll get heaps bigger buds if you use a combination of mh and hps during flowering, but i have no clue about using a mh during the first 3 weeks of 12/12 to reduce stretching sorry

[SukonmiSkunk]

ultimately what should be done... is add the HPS for flowering leaving the MH in there... but 99.999999% this is just never an option.. heat, power, cost...and space..

 

so the better option is MH for veg and HPS for for flower....

I wouldnt say controlling the internodal spacing by using MH for the first 3 weeks of flower would be a good idea. Almost all plants stretch out and usually fill out by the time they are finished... Ive flowered under a MH and altho it works.. the buds will not fill out as much... you would be just holding them back....

 

1000 watters can do a space 5'x5' with excellent results.... they can be stretched to 7'x7'... I would choose a space around there somewhere...

you will need at least one 250 exhaust fan...

Edited February 22, 2006 by SukonmiSkunk

[Frazz]

... Ive flowered under a MH and altho it works.. the buds will not fill out as much... you would be just holding them back....

 

I have the greatest respect for your vast experience in these matters SS

 

but i have grown shiva skunk under 3000w of MH from start to finish

and i kid you not, they were solid tight and hard.....compareable with the look of White Heaven :reallyexcited:

so maybe it just depends....on what i dont know :scratchin

 

[keepleft]

hey SS, my 1000w are covering 1 square meter each! so theres no room to squeeze in the HPS with the MH (believe me if it was an option id have em all squeezed in like a greedy prick!). and dont worry about the exhaust as there are 12inch 500 watt fans coming in and coming out so it blows a gale in there!

 

by the way the advice i initially posted comes from a distributor of the lights.

 

 

perhaps i should leave 1/3 of the lights as MH during flower and 2/3 as HPS? instead of pure MH for 2 weeks and HPS thereafter?

[SukonmiSkunk]

mate my 600's do a space of 4'x4' so 1mx1m will be too small.. a 600 or even a 400 would do ok in there.. 600, preferably.....

 

they will cook in that space, I reckon... you will need a montsa out fan.... the room will be like a windtunnel to keep the heat down....

 

yeah Frazz,

I did the first 2 years of my career with a MH and it was fine, really... just the fact when I started the HPS were twice the price... about $700..... I did however finally buy the HPS and never looked back.

 

It is prooven fact the reds and yellow spectrums are needed for flower production.... all spectrums are present in both globes but the HPS is more reds and yellows...where as the MH is more UV... blue... clearly seen when they fire up...

 

I dont doubt at all that the shiva under MH would compare with my WH... but they are only 600's remember and I have seen shiva buds growing bigger than my legs, almost 10inches in diametre, they were in a warehouse tho....... so maybe under the HPS they might have been bigger...

 

with the shiva I seen, it took 14 weeks to flower... and I know theres one that gets done in about 9.... so there might be a difference

 

either way ya go both globes will produce and to tell the trueth, I didnt notice that much in difference in final yeild.... maybe slightly higher with the HPS, but only by a few ounces...

[Frazz]

Yeah thats what i started off with 1000w MH, but hardly use em now

i had the shiva in 9wks...was real lucky, but lost the strain

[SukonmiSkunk]

Frazz I might have had the Shiva Shanti.... this shit was unreal... I mean the amount of branches was phenominal..like in an inch of stalk about 15-20 knodes... it looked like it was flowering during the veg cycle

 

nothing wrong with MH tho just better with the HPS i reckon

[keepleft]

so the consensus is just go straight to hps when going 12/12 ??

 

ss - temps dont get over 30degrees celcius. no probs with that. ive got 600's and provided u keep the temps down they dont compare to the 1000's. u can never have enough light imho provided the temps are controlled!

[thc24]

Hi SS where can i find some pics of the White Haven , wouldnt mind a looksy . Wow Keepleft monsta fan there 500 wt shit my inlines are only 16wt .

Many sweer by the MH but usually 50/50 hps my first light was MH and really lacked what the hps puts out in early flower. My 600s cover 1.5 x 1.0 meter each . For short nodes a preveg under flouros does wonders but only for a week or so. What sort of hps globes you guys using found the luca to out last and preform better in third grow or after 4 months use.