HPS lights question
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Paperhouse
Active Member
No, you'll be fine. MH is generally preferred for veg but if you're on a budget an HPS will work.
collective gardener
Well-Known Member
We've found that MH will give you much tighter node spacing in veg...meaning more yield in bloom. HPS in veg won't "hurt" your plants, but it will affect your yield.
https://www.rollitup.org/indoor-growing/407048-20-000-watt-medical-grow.html
https://www.rollitup.org/indoor-growing/407048-20-000-watt-medical-grow.html
Jack Harer
Well-Known Member
I've run several grows under MH for both veg and flower, HPS both veg and flower, and a mixed spectrum both stages. No visible or discernible difference in inter-nodal spacing, yield or bud density. There are many threads on that very issue. In. fact, with most REALLY experienced growers (way more experience than me) I've been associated with, their new school of thought is to do both cycles with a mixed spectrum, and a 20/4 light cycle in veg. But to answer your Q, you'll be just fine with HPS both stages.
DinafemHashPlant
Active Member
agreed^^^...
Paperhouse
Active Member
How does that work exactly? I've never seen any discussion regarding 20/4 for flowering. Don't photos require at least 12 hours of darkness to go into flowering?
IslandDelight
Active Member
show something to back this up? 20/4 in veg maybe but I never heard of it in flower. That would seem to give a huge advantage in the bud department but it's a secret?
collective gardener
Well-Known Member
I'm with Island. Just what in the fuck are you talking about? "Really experienced growers?" Of the half dozen or so commercial grow ops I deal with here in Cali (all 20K watt+ operations), none use mixed spectrum. All either use just T-5's or MH in Veg. There's plenty of pics on my thread to back this up. Most "experienced growers" I know veg for so little time, T-5's do just fine. I have yet to see a well run commercial op with mixed spectrum in veg. Keep it simple and stick to basics that work: MH in veg, HPS in bloom. Done.
Jack Harer
Well-Known Member
NO!!! NOT in flower. I gotta edit that. Thats what happens when I post before my first pot of coffee!!! Thanx for bringing that to my attention. MAN what a fuck up!!! 12/12 in flower only!!!
Jack Harer
Well-Known Member
Not saying that its graven in stone. Having re-read the post, looks like it came out badly. I should have said growers with more experience than I. Sorry.
I grow out clones, but I veg them a good bit (60 or so days) 'cuz i'm lollipopping mine for one main only. So i do veg them longer than most people. I also am involved with some people here on the east coast who are more into the research than most folks that I PERSONALLY know. These are the findings we have come up with. NOTHING EMPIRICAL would support that it is the only way to fly. Just that it is what I used to get the results I got.
I most certainly did not mean to cast aspersions on anyone's knowledge or abilities.
symbiote420
Well-Known Member
I just got into a heated debate on another thread about this very topic. There are some cranky ass know-it-alls on RIU they believe they know everything about this plant, and that's just not the case. I've been growing my whole life, 22 yrs of cultivating mj and I still learn something new almost everytime I grow. I can say what works for somebody else might not work in your situation, and if you getting good results strive for better. I have friends young and old alike I showed how to grow and I pick up shit from their grows all the time, a child can teach a man something if he can open his mind to accept where it is coming from, you better believe it! Some ppl use hps for veg, the majority of growers use flos and mh cause that's the standard, you don't have to be standard you wanna veg under your hps or a mixed spectrum go right ahead this shit is like asking dirt or dro, indica or sativa somebody's not gonna say sativa then somebody's gonna post he's a dumb ass....blah,blah,blah,....yadda,yadda,yadda who died and made these ppl Ganja Gods, grow as long as I have and you'll learn that harvesting has more to do with luck than anything else.
many people use both with great results, personally i use and 150 hps and cfls for my veg and have never had any problem with stretching. i am sure many people use mh with great results. lets put aside our anecdotal evidence and examine the science behind this. i wish to broaden this discussion and just because my perspective and opinion differs than yours does not mean i am attacking you. if you cant discuss ideas passionately than i suggest you go elsewhere. to those who wish to debate this please respond logically and relevantly.
heres the thing. lets read abit about photosynthesis and the molecule which absorbs light. here is some info i have copied and pasted:
Chlorophyll as a Photoreceptor
Chlorophyll is the molecule that traps this 'most elusive of all powers' - and is called a photoreceptor. It is found in the chloroplasts of green plants, and is what makes green plants, green. The basic structure of a chlorophyll molecule is a porphyrin ring, co-ordinated to a central atom. This is very similar in structure to the heme group found in hemoglobin, except that in heme the central atom is iron, whereas in chlorophyll it is magnesium.
There are actually 2 main types of chlorophyll, named a and b. They differ only slightly, in the composition of a sidechain (in a it is -CH3, in b it is CHO). Both of these two chlorophylls are very effective photoreceptors because they contain a network of alternating single and double bonds, and the orbitals can delocalise stabilising the structure. Such delocalised polyenes have very strong absorption bands in the visible regions of the spectrum, allowing the plant to absorb the energy from sunlight.
The different sidegroups in the 2 chlorophylls 'tune' the absorption spectrum to slightly different wavelengths, so that light that is not significantly absorbed by chlorophyll a, at, say, 460nm, will instead be captured by chlorophyll b, which absorbs strongly at that wavelength. Thus these two kinds of chlorophyll complement each other in absorbing sunlight. Plants can obtain all their energy requirements from the blue and red parts of the spectrum, however, there is still a large spectral region, between 500-600nm, where very little light is absorbed. This light is in the green region of the spectrum, and since it is reflected, this is the reason plants appear green. Chlorophyll absorbs so strongly that it can mask other less intense colours. Some of these more delicate colours (from molecules such as carotene and quercetin) are revealed when the chlorophyll molecule decays in the Autumn, and the woodlands turn red, orange, and golden brown. Chlorophyll can also be damaged when vegetation is cooked, since the central Mg atom is replaced by hydrogen ions. This affects the energy levels within the molecule, causing its absorbance spectrum to alter. Thus cooked leaves change colour - often becoming a paler, insipid yellowy green.
As the chlorophyll in leaves decays in the autumn, the green colour fades and is replaced by the oranges and reds of carotenoids. Chlorophyll in Plants
The chlorophyll molecule is the active part that absorbs the sunlight, but just as with hemoglobin, in order to do its job (synthesising carbohydrates) it needs to be attached to the backbone of a very complicated protein. This protein may look haphazard in design, but it has exactly the correct structure to orient the chlorophyll molecules in the optimal position to enable them to react with nearby CO2 and H2O molecules in a very efficient manner. Several chlorophyll molecules are lurking inside this bacterial photoreceptor protein (right).
as you will notice in the graph above we can clearly see the two zones where light is absorbeed and we can see that there is a higher light absorbtion in the 400nm-500nm range than in the 600nm-700nm range. now lets look at light spectrum and light sources here we will compare hps and metal halide:
Metal Halide (MH) can reach internal pressures upwards of 600 psi, and internal temps up to 3000* so good airflow all the way around the bulb is a must, also one MUST be sure to wipe the bulb down well before lighting it because oils from your fingerprints will burn the bulbs out pretty quickly. these are slightly more expensive, require a ballast (and therefore a limited amount of wiring knowledge, and are not widely available. Common places that sell them only have a limited number and not very many different spectrum or outputs.
MH bulbs produce a natural, white light and are well suited for veg and/or flower stage (though they are most commonly used for vegetation).
MH is a High Intensity Discharge (HID) bulb that is also quite efficient. However, of the 3, this will require replacement most often due to several of the metal halides used (such as sodium and mercury halide) being very reactive and converting and deteriorating over multiple cycles.
Next is the ever so popular High Pressure Sodium
High Pressure Sodium (HPS) is another HID bulb that reaches pretty high internal pressures and temperatures, so again good airflow and wiping the bulb down are a must. HPS bulbs are great because they produce a good spectrum for veg and/or flowering (though better suited for flowering) and also are efficient producing like 100 lumen per watt.
these bulbs also require a ballast, and are about the same as MH as far as availability. your best bet is the internet. sodium is also HIGHLY reactive and will therefore slowly deteriorate after multiple cycles and require bulb replacement, though not QUITE as often as MH
now if we examine the three graphs in relation to the chlorophyll graph above we can see that both lights spike in the 500-620nm range. but as you can see the mh gives out light throughout the entire spectrum while the hps gives off most of its energy in the 500-620nm range.
now we might look at this and say well its obvious, the mh gives a wider spectrum and therefore must be better. but the hps is more efficient than the mh and if we count the volume of use able light which an hps would give off compared to a mh then the hps is more efficient .
heres the thing. lets read abit about photosynthesis and the molecule which absorbs light. here is some info i have copied and pasted:
Chlorophyll as a Photoreceptor
Chlorophyll is the molecule that traps this 'most elusive of all powers' - and is called a photoreceptor. It is found in the chloroplasts of green plants, and is what makes green plants, green. The basic structure of a chlorophyll molecule is a porphyrin ring, co-ordinated to a central atom. This is very similar in structure to the heme group found in hemoglobin, except that in heme the central atom is iron, whereas in chlorophyll it is magnesium.
There are actually 2 main types of chlorophyll, named a and b. They differ only slightly, in the composition of a sidechain (in a it is -CH3, in b it is CHO). Both of these two chlorophylls are very effective photoreceptors because they contain a network of alternating single and double bonds, and the orbitals can delocalise stabilising the structure. Such delocalised polyenes have very strong absorption bands in the visible regions of the spectrum, allowing the plant to absorb the energy from sunlight.
The chlorophyll molecule is the active part that absorbs the sunlight, but just as with hemoglobin, in order to do its job (synthesising carbohydrates) it needs to be attached to the backbone of a very complicated protein. This protein may look haphazard in design, but it has exactly the correct structure to orient the chlorophyll molecules in the optimal position to enable them to react with nearby CO2 and H2O molecules in a very efficient manner. Several chlorophyll molecules are lurking inside this bacterial photoreceptor protein (right).as you will notice in the graph above we can clearly see the two zones where light is absorbeed and we can see that there is a higher light absorbtion in the 400nm-500nm range than in the 600nm-700nm range. now lets look at light spectrum and light sources here we will compare hps and metal halide:
Metal Halide (MH) can reach internal pressures upwards of 600 psi, and internal temps up to 3000* so good airflow all the way around the bulb is a must, also one MUST be sure to wipe the bulb down well before lighting it because oils from your fingerprints will burn the bulbs out pretty quickly. these are slightly more expensive, require a ballast (and therefore a limited amount of wiring knowledge, and are not widely available. Common places that sell them only have a limited number and not very many different spectrum or outputs.
MH bulbs produce a natural, white light and are well suited for veg and/or flower stage (though they are most commonly used for vegetation).
MH is a High Intensity Discharge (HID) bulb that is also quite efficient. However, of the 3, this will require replacement most often due to several of the metal halides used (such as sodium and mercury halide) being very reactive and converting and deteriorating over multiple cycles.
Next is the ever so popular High Pressure Sodium
High Pressure Sodium (HPS) is another HID bulb that reaches pretty high internal pressures and temperatures, so again good airflow and wiping the bulb down are a must. HPS bulbs are great because they produce a good spectrum for veg and/or flowering (though better suited for flowering) and also are efficient producing like 100 lumen per watt.
these bulbs also require a ballast, and are about the same as MH as far as availability. your best bet is the internet. sodium is also HIGHLY reactive and will therefore slowly deteriorate after multiple cycles and require bulb replacement, though not QUITE as often as MH
now if we examine the three graphs in relation to the chlorophyll graph above we can see that both lights spike in the 500-620nm range. but as you can see the mh gives out light throughout the entire spectrum while the hps gives off most of its energy in the 500-620nm range.
now we might look at this and say well its obvious, the mh gives a wider spectrum and therefore must be better. but the hps is more efficient than the mh and if we count the volume of use able light which an hps would give off compared to a mh then the hps is more efficient .
symbiote420
Well-Known Member
Plants use PAR (photosynthetically active radiation) to fuel growth and MH produces more PAR per watt than HPS does, they have a higher CRI (color rendering index) and a more fuller spectrum even though they have less lumens. I bought a SunMaster 1000 watt warm halide last year guess I'm bout to fix my old ballast to do a test grow with it! Whatever you choose to do I think will produce good results, just get growing.
then why dont you grow with leds? they can produce the most par?
iNFID3L
Well-Known Member
symbiote420
Well-Known Member
One day I will, when the technology gets a little better! I know PAR isn't the only equation in the matter, theirs intensity, spectrum, etc. All these come into play when a plant grows, plants use more than just red, white, or blue light, the sun has every color of the spectrum in it, they're green because they don't absorb that color they reflect/bounce it back. I have an associate who uses LEDs for side lighting with HPS his growth is off the chain. "My choice" is bluer spec. for veg/ redder for flower, there's blue skies spring/early summer during veg time, reddish skies mid summer/fall during flower, nature has been using that formula for millions of years my grandmother put me up on that when I was a kid and she didn't know shit about MH or HPS lights indoors.
collective gardener
Well-Known Member
Well said, my man. Part of the great fun of growing is trying new stuff. I, too, learn new techniques all the time from people with both way more and way less experience than myself. These days, I'm a very conservative grower. Too many times I've seen a new technique work wonders for someone else's grow op, only to employ it myself with horrible results. With an op our size, we really can't afford to do much "trial and error". When I first built this latest op, I was trying all kinds of new stuff. A couple things didn't go so well and cost us some real $$$. So, I reeled myself in and got right back to the basics that I know work...and work very well. I really miss trying new things. So much so that we're building a couple isolated flower rooms just for trying new things side by side with our existing techniques. As we discover effective new techniques, strains, and equipment, we can incoorporate them into the main grow. In the meantime, the main grow keeps on producing. Ironically, my current op looks almost identical to my closet op in 1990...just about 50 times bigger! In those 20 years I've employed every possible method, yet came full circle to what I learned back in the late 80's from a book called "Indoor Marijuana Horticulture". Even my nutes are almost the same.
I apologize to Jack Harer for my reaction to what I now know was a simple typo. It just makes me very angry when people give bad advice to folks just getting started (I'm speaking of the 20/4 blooming typo). I'm not sure if it's better or worse to start growing in the age of the internet. On the one hand, there is a wealth of information. On the other hand, so much info is available (much of it conflicting) that it must be very confusing to noobs. I'd still advise all new growers to buy a good book on growing so that they can learn the basics without being distracted.
https://www.rollitup.org/indoor-growing/407048-20-000-watt-medical-grow.html