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MH vs HPS in bloom

if anyone is interested though

i know tons of guys in bc whom put the bigger caps on their 1000 watt core n coils. they claim to get up to 1500 watts per bulb output. but you can only use cheapy silvanias or phillips and they need replacing every crop or 2 becuase of the high output

med-man

Core and coil, you mean the magnetic ballasts?
 

med-man

The TRUMP of SKUNK: making skunk loud again!
Boutique Breeder
ICMag Donor
Veteran
hey provision

yes, magnetic

med-man
 

southflorida

lives on planet 4:20
Veteran
Any lamp with a high amount of green in the spectrum will give you a much higher lux reading. In general when you use MH you need 30-50% more lamps/wattage to obtain the same ppf a good horti HPS will give you. Though a MH will look very bright to the human eye, it's not that it actually outputs more photons in the PAR spectrum, and that's what drives photosynthesis: the number of photons in the right spectrum.

Now there is a lot of difference in HPS lamps when it comes to efficacy. Some HPS lamps do just over 1.6 umol/W, while the best do 2.1 umol/W. MH usually doesn't go any further than 1.2 - 1.5 umol/W (and have a really bad light maintenance). The new CMH do 1.7-1.9 umol/W but are only medium wattage, so it will be interesting to see what the new high wattage lamps do you see pop-up sometimes.

But anyways, if you replace a bad HPS lamp with a good MH I think you can have a better yield and a better quality because of the improved spectrum. However, if you are going to replace a really good HPS with a bad MH then you could lose about 30-50% of your total ppf easily. That amount you can't make up with a better spectrum.

That's another reason why you should measure umol instead of lux: there is more than enough scientific evidence that there is a very strong correlation between the photosynthesis and the amount of par light. That's scientific.

I did numerous side by side tests (yeah I enjoy a good scrog) where I made sure that the plants received the same amount of PAR light, but from different light sources. In all the different grows I saw mostly quality/health/morphogenetic differences, yield differences were minor at the same PPFD with comparable reflectors (also important). Now that I don't call science, but experience. ;)

(ps the white sensors you see once in a while are the RH/T/CO2 dataloggers)

Hi whazzup! Love reading your posts here and on og. I watched the video in your post above, and I was wondering what was the difference between the highs from each light source? Which samples were the best? Were any of them not satisfactory to you?
 

Hash Zeppelin

Ski Bum Rodeo Clown
Premium user
ICMag Donor
Veteran
cool. i just run super lumens. 4400 watts (4x1100) in 10x10 tents. its so bright i get light penetration to the floor even in the corners. i click down to 600 or 750 in veg for first week. I dont care if I am efficient. I dont get larf. Sorry if I'm not green. lol
 

3rdEye

Alchemical Botanist
Veteran
so does anyone else have any thoughts on disposing of all these bulbs? I know most HID bulbs have good amounts of toxic heavy metals in them, so just tossing them in the trash doesn't seem like a good idea.

I don't mind if my bulbs lose some overall output as long as the light quality remains reasonably consistent.
 

med-man

The TRUMP of SKUNK: making skunk loud again!
Boutique Breeder
ICMag Donor
Veteran
i also heard hoedepot has ratted out growers for unodinary purchases like too many bales of dirt, indoor gardening stuff mid winter etc

please be tactful with where you park and how you return them

med-man
 
A

acridlab

good call. but in all fairness you have to be careful like that everywhere you go,, around michigan its a fact that most grow shops are informants.. definitely feel safer going to a big store with my hat low, lol
 

med-man

The TRUMP of SKUNK: making skunk loud again!
Boutique Breeder
ICMag Donor
Veteran
just make 3 uturns on your way home. in a renta car lol

med-man
 

Jhhnn

Active member
Veteran
i also heard hoedepot has ratted out growers for unodinary purchases like too many bales of dirt, indoor gardening stuff mid winter etc

please be tactful with where you park and how you return them

med-man

That's likely a few jerks in a few locations.

Just sayin'.
 

Fly by Night

Like a Wing
Veteran
Gnome, vaped, lovely bouquets y'all arranging! Gotta ax, why prefer the bulbous bt56 over the 37 type reduced envelope. The arc seems equal, what's the diff folks?

Thanks much bruvvies
 

the gnome

Active member
Veteran
why do I run the 4000K sylvie 1000W MH with the BT56 bulb?
because it did the same as my hps AND it only costs $19.64 :smoke:

yo... fly by nite,
it's the 4000 Kelvin rating thats Key,
that's the sweet spot to using MHs in bloom.
the large BulbType rating is incidental to the design of the 64468 Sylvania Metalarc
and that bulb is cheepcheepcheep @$19.64 :)
 

the gnome

Active member
Veteran
I just glance at the bulb, while squinting!

lol...I'm a squinter from way back :biggrin:


4000K run in both veg-n-bloom takes it from start to finish no issues with nearly every strain ive run under it
1 thing tho, its universal burn position bulb but the sylvie i listed above tends to change color if used horizontally.
the 6400+K solar max and sun master halides ive used don't have this prob but they're lister horz only i think.
i use the parabolic hoods so it's a non issue for me.
 

jerzu19

Well-known member
Veteran
Hi guys
I have question for Pro Growers,I use a 150w Hps with Philips CDMt 70w(4200k) in my growbox.
But the problem is that the box heve two "sides color" I mean that the left side of box is controled by hps light and the right side i more CDMt.My question: Can this specific "sides color" infect some stress to plants,coz one of them are more on hps side and one more on CDMt light.
Some pics for better understand
picture.php

This pic (CDMt add for last 3 weeks of flo)dont show the best this "side color" but.....
In current grow I have larger,more bushy plants and one of them are half on hps side and half on CDMt siede and thats my problem!Its stresing her ?????
Help willl be much appriciated.
 

dimebag_

Active member
why do I run the 4000K sylvie 1000W MH with the BT56 bulb?
because it did the same as my hps AND it only costs $19.64 :smoke:

yo... fly by nite,
it's the 4000 Kelvin rating thats Key,
that's the sweet spot to using MHs in bloom.
the large BulbType rating is incidental to the design of the 64468 Sylvania Metalarc
and that bulb is cheepcheepcheep @$19.64 :)

Gnome-wassup brotha…. interesting thread. Are you still rocking an MH all the way thru flower? I was looking at some grabbing some Digilux 1000W 4000K bulbs to try out to see if they would work similarly. WDYT? Not too many 1000W hps options in a 4000K rating. I currently run Hortilux 1000W hps in an air-cooled set-up, so I can't run vert bulbs at the moment.

I was curious if you've ever used double-ended hps and how it mite compare to running a 4000K MH. I think double-ended is my next upgrade after I seal my room an install ac and dehumidifier. But I was thinking about trying out some MH in the mean time. thanks

cheers
dbag-
 
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