ZTELTHY NEEDS HELP !!! :- WITH KELVIN |(K-Rating)...

Hi, as many of you prob. know I am building a stealth cab.. and have decided to up my Watts, from 100W HPS, to a Dimmable 250W HPS... I plan to use a 250W metal halide for veg, but am stuck between 2 lamps... one of them is a 6500k metal halide........and the other is a 6500k & 8000k "Dual Arc" metal halide... !??

My heads telling me a dedicated 6500k would be better, but I cant help but think having the extra spectrum of the 8000k arc as well ~ may be more benificial ??

Another thought is I could use a Dual Spectrum 250w HPS, but whether or not this would be better than the MH for Veg is again a question I need to ask ??

And lastly for best results in flowering should I use a 250w Dual Spec HPS aka: 1X 250w DigiLux Dual Spectrum HPS/Sun Master 250W, or a normal 250w Osram HPS Lamp

I own lots of HPS and METAL HALIDE Lamps....but knowing which to use is becoming a bit of a nightmare and I am super high as well lmao..So my thinking process is running slowly at best today..

Any 'light' shon on this topic would be very well received, (pun half intended lol) .. and +REP Will be rewarded in receipt

Cheers - ZTELTHY

http://www.ebay.co.uk/itm/New-Super-250W-watt-Aquarium-Reef-Twin-Arc-Metal-Halide-Light-Bulb-Mogul-E39-/390428705133?pt=LH_DefaultDomain_0&var=&hash=item5ae75d416d

Above is a LINK to the 250W DUAL-ARC MH 6500k/8000k lamp.

From what I understand the 6500k and the 8000k arc's fire up only 1 at a time ....so one-day the plants would be under 6500k then the next day they would be under 8000k then the next day back under 6500k...I dunno if this would be good or not but the lamp looks impressive just need to know if 8000k does anything extra for the plants....I mean it is a marine/coral life lamp with high PAR! but whether this would be useful for a land plant ? ? ? . - ZTELTHY

I never used a dual arc bulb but im sure it will give you a even mix of short and bushy and tall and leggy.

Forgot to add that some people who bought the arc bulb didn't like it cuz it gave 1 plant 2 different looks,so my theory above would be flawed in a big space.

I will try n find a kelvin color ratio chart n see where 8000k is and hopefully find out how it will work in conjunction with Vegging - ZTELTHY

Me personally would stick to the MH i was actually looking into buying a dual 2 days ago but it didn't seem worth it and if it was im sure many more growers would use it.
Probably why the bulb above is for an aquarium.

HotShot7414 said:

I never used a dual arc bulb but im sure it will give you a even mix of short and bushy and tall and leggy.

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If I could find exactly how the 8000k will have an effect on the plant before I commit to buying the lamp, I plan to scrog under the lamp but also want lots of nodes etc.. - ZTELTHY

HotShot7414 said:

Me personally would stick to the MH i was actually looking into buying a dual 2 days ago but it didn't seem worth it and if it was im sure many more growers would use it.
Probably why the bulb above is for an aquarium.

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Yeah! I have a feeling your right still...if anyone has any more info on running an 8000k MH for Veg etc... that'd be great - ZTELTHY

Ok I've done some research and apparently the lower the Kelvin the better the lamp for Flowering...BUT-!!! I am confused.. You see : 2700K is the norm and recommended Kelvin rating, However the Sun-Master Dual spec HPS runs at 2000K (a drop of 700K)..

..does that mean any lamp running 2000k is considered "Dual Spectrum" ? ......I'am also wondering is it better to go any lower than 2000k say 1900k or maybe lower still ?? or is a single 250W 2000k the best possible lamp I can get with the best possible spectrum ?? - ZTELTHY

BUMP! - ZTELTHY

just look at the charts but if it rated at 2000k instaead of 2700k this is the difference, 2000k not better

View attachment 2373942

see the spike in the blue section and how low it is? this is the sylvania 2000k.


this is the avg 2700k disregard the "more energy" they just use a different combination of chemicals so it shine blue light in addition the red.(with the sacrifice of some red)

honestly kelvin is the worst way to know what bulbs to get. but all in alll 2700k is more geared towards horticultural use.

its just better to look at the chart ans ee which has more PAR value than it is to go from the kelvin ratings.

Whats the best kelvin rated lamp for the extreme reds that dont get accounted for at the end of the scale for both standard Son-T HPS and Dual spectrum lamps? (so the spikes peak like the yellow's !??)


http://www.kessil.com/products/h150w_led_grow_light.php

^ I've seen these KESSIL Red 150W LED lights that offer a better red on the nm scale... they are pretty expensive...and I would prefer a 250W HPS E-40 that would do the same thing or better..

That way I could run a 250W 6500K MH for Veg, progress to a 250W 2000K Dual-Spec HPS for late Veg & early Flower and then change to which ever light source offers me the extreme reds for mid to late Flower..

anyone know of an HPS lamp than can do pretty much what the KESSIL 150W Red can do ?? and if so at what KELVIN rating .. - ZTELTHY

The Sun Master Dual Spec HPS lamps seem to offer high peaks for both Blue, Yellow, and Reds (see LINK) !? ...maybe it'd be best to stick with this... and possibly add the KESSIL 150W Red LED thing as well..thoughts ?? - ZTELTHY

Ztelthy said:

BUMP! - ZTELTHY

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Jesus calm down lol

not sure about the veg light BUT I would highly recommend using the old dual Spec HPS in flower they run a touch warmer than standard HPS but the extra blue they provide really frosts those bitches up towards the end!

use the dual spec for early flower than a regular HPS for late flower as it will have a lot more red than the dual spectum bulb which is a 125w MH red spectrum and 125 HPS red spectrum a pure 250w HPS of any brand would beat the red over all form the dual spec. IMO for electronic ballasts i would get either Ushio or Digilux.

for a mag ballast phillip or hortilux

polyarcturus said:

use the dual spec for early flower than a regular HPS for late flower as it will have a lot more red than the dual spectum bulb which is a 125w MH red spectrum and 125 HPS red spectrum a pure 250w HPS of any brand would beat the red over all form the dual spec. IMO for electronic ballasts i would get either Ushio or Digilux.

for a mag ballast phillip or hortilux

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So a standard 2700k is best for flower ... ? is there a stage further I can go or is there a stage better I can go for 'Late Flower/Bud' than 2700k ?? - ZTELTHY

yes to first ?, no to 2nd. it will just be more yellow and green. 2700/2900k(this all depends on the math used to get the number from the spectural graphs and how they want to market it) is optimal for current HPS design, the most PAR and least amt of usless light. the amt of red is gonna be equal no matter what design but the rest of the spectrum can differ.

if you wan to get a broader Red spectrum for flower you will need T5 and or Leds. i mentioned T5 and flouro in you thread already but you did not seem interested.

if i where you and i could cram all thin in there i would use
x2 26w Reptiglo 10.0 Uvb cfls, x2 coralife colormax 24w t5ho, and the 250w HPS ( MH for first 2 weeks then the regular HPS scratch the dual spectrum.)

the colormax T5 has all the deep reds your missing but not all the red the HPS provides so its a perfect match up, plus they still put out some blue and not much wasted energy on yellow and green, althoug as much as i calll it wasted energy this is not true, remember yellow and green are vital wavelengths just not in overabundance they are needed in the right ratios with reds and blues to be utilized effectively..... thus all the led manufacturers recent design changes to include white leds.

combinations of lighting types will always beat single source lighting hands down.