GAVITA Pro 1000 DE

[plumbum]

hi, i am looking for help! we are trying to figure our the best possible lighting layout for 15' x 29' room with gavita lights, ceiling is 11.5'. we have never used this lights before and would love to get a feedback from experienced users.

After reading lots of complains here about too much light and bleaching we are wondering what is the best way to go:

a) light a room by Gavita's advice and provide around 1000 umol for entire room?

or

b) go with something like Caravaggio advices - 3 lights per 2 4x8 tables

our goal in this situation is maximum output from the room, # per light not as important.

we are considering using rolling tables to maximize working space.

do you guys think that 1000 umol could be too much??

thank you for your help. any advice is welcome and greatly appreciated!

 

[Beta Test Team]

Yes, 1,000 umol is too much (especially per day), and the way Gavita measures that umol is also not correct, or, should I say, not the 'whole picture'; it's not the average of umol over 3'x3' that matters, but the umol per much smaller area, this is about uniformity, which Gavita severely lacks.

For example, to reach 1,000 umol average, there will be spots on the canopy with well above 1,200, up to 1,500 umol, as well as spots that are well below 600 umol, down to 200 or 300 umol.

If your number of fixtures isn't important, and you really want to use Gavita, I would pack them in and dim them to somewhere between 60% and 80%. That way you can reach a target umol (like 800, or 1,000 if you wish) while also having better uniformity than you would if running Gavita's at 100% and using fewer of them.

Oh yea, without a quantum sensor (https://www.icmag.com/ic/showthread.php?t=298086) you really can't be sure what umol you're providing. You can't go by Gavita's suggestions because each room is different in terms of various factors affecting radiation.

https://www.icmag.com/ic/showthread.php?t=297147
https://www.icmag.com/ic/showpost.php?p=6789995&postcount=10
https://www.icmag.com/ic/showpost.php?p=6790112&postcount=12

 

[plumbum]

Yes, 1,000 umol is too much (especially per day), and the way Gavita measures that umol is also not correct, or, should I say, not the 'whole picture'; it's not the average of umol over 3'x3' that matters, but the umol per much smaller area, this is about uniformity, which Gavita severely lacks.

For example, to reach 1,000 umol average, there will be spots on the canopy with well above 1,200, up to 1,500 umol, as well as spots that are well below 600 umol, down to 200 or 300 umol.

If your number of fixtures isn't important, and you really want to use Gavita, I would pack them in and dim them to somewhere between 60% and 80%. That way you can reach a target umol (like 800, or 1,000 if you wish) while also having better uniformity than you would if running Gavita's at 100% and using fewer of them.

Oh yea, without a quantum sensor (https://www.icmag.com/ic/showthread.php?t=298086) you really can't be sure what umol you're providing. You can't go by Gavita's suggestions because each room is different in terms of various factors affecting radiation.

https://www.icmag.com/ic/showthread.php?t=297147
https://www.icmag.com/ic/showpost.php?p=6789995&postcount=10
https://www.icmag.com/ic/showpost.php?p=6790112&postcount=12

Beta Test Team, thank you for your reply. If 1000 umol is not optimum and indeed too much, what is the optimum number for flower room from your opinion?

After seeing few lighting plans provided from Gavita it looks like uniformity is there when many units are used. But again, I've never tested it personally.

I am not sure yet if we will test actual umols, most likely lux for uniformity of lighting and dial everything according to the plants needs. I'd like to get a good starting point.

Yes I am still set on Gavita after many positive reviews. And it's not like the price of set up is not important and budget is unlimited. But if by using few extra lights we would be able to have a bigger total number it would be still worth it.

 

[Beta Test Team]

You're wecome. The umol you use depends strongly upon the photoperiod you want to use. For veg. around 600-800 umol is what I'd consider ideal, and for flowering around 700-900 umol.

The layout Gavita suggests doesn't provide enough overlap to increase the uniformity a good deal. That's why I suggested dimming them and packing more in per area, to get better uniformity. (If it were me, I'd go with ePapillion.)

If you're going to buy a lux meter for uniformity testing that's better than nothing, but having a good quantum sensor really should be seen like the necessity of having a good pH pen, or EC pen. If your budget is unlimited, than you really should by a LI-COR LI-190 and 250SA (quantum sensor setup), it's only like $1,000. Being able to measure the radiation as used by the plants is really so very useful for all kinds of reasons, including for different growth stages, like cloning, and keeping mothers (all growth stages have ideal umol ranges).

You can't dial in radiation without knowing how much you're providing. You can't look at the plants and use them as a guide, at least not if you want optimal growth, yield, and radiation use efficiency (especially over time as lamps dim).

 

[TheArchitect]

You're wecome. The umol you use depends strongly upon the photoperiod you want to use. For veg. around 600-800 umol is what I'd consider ideal, and for flowering around 700-900 umol.

I've come to the conclusion that lower intensity creates better flowers. I've also realized that to get the same DLI with less intensity you need longer photoperiod, I've pushed it to 13/11.

So in layman's terms, use bigger footprints, raise the lights, and run longer lights on during flower. An added benefit is yield increases.

 

[GET MO]

architect,when you do the 13/11 how does it effect overall flower times? not sure it would make them decrease because increase in production time or increase because they wouldn't have that "rush to finish" push that a 12/12 gives them...

 

[plumbum]

thanks again Beta Test Team, really appreciate your input. In a large room Gavita advise is to use 1m between the lights in the row and 2.1m between rows (edges and the walls is different story). This should provide around 1000 umol at 1 meter height. I wonder what is the way to scale it down by 10-20% and keep uniformity. Maybe i should send Gavita request to provide lighting layout for 750W at 800 umol across the room?

Budget is definitely limited, but if umol reading provides so much extra information then Lux (we do have a meeter already).. we might purchase it between few people to share. By the way - what is a good place to buy it?

 

[plumbum]

TheArchitect - 13/11 - you got me interested.. what lighting plan works best for this altered times? and what umols are you shooting for, if you have this numbers?

thank you

 

[Beta Test Team]

thanks again Beta Test Team, really appreciate your input. In a large room Gavita advise is to use 1m between the lights in the row and 2.1m between rows (edges and the walls is different story). This should provide around 1000 umol at 1 meter height. I wonder what is the way to scale it down by 10-20% and keep uniformity. Maybe i should send Gavita request to provide lighting layout for 750W at 800 umol across the room?

I wouldn't take Gavita's word on it. Best thing to do: buy a few fixtures and install them in a few different scaled-down mock-ups of your room, and using your quantum sensor dial in both the uniformity (lower difference between high and low umol per area) and the umol.

Check out the two bottom links I posted in my first post to you above. In those posts I described this in greater detail.

Budget is definitely limited, but if umol reading provides so much extra information then Lux (we do have a meeter already).. we might purchase it between few people to share. By the way - what is a good place to buy it?

Buying a unit to share is definitely a good idea.

You can only buy LI-COR equipment from LI-COR, I believe. And they generally don't sell to the general public, but to scientists, companies, and other organizations. You can buy it as a member of the public, but they will likely ask you some extra questions.

When you buy it they'll contact you to make you agree you're not going to re-sell it or ship it to Iran (seriously), and they'll ask you what you're doing with it, what you're researching. To answer the 'what you're researching' question just write a short description of some radiation related plant science research, but don't mention Cannabis and make sure the research description sounds like a scientist wrote it and it's well written.

 

[Beta Test Team]

TheArchitect - 13/11 - you got me interested.. what lighting plan works best for this altered times? and what umols are you shooting for, if you have this numbers?

thank you

Check out this thread, where I wrote a lot about how changing the photoperiod affects not only total umol per day (which is often more important than PPF), but also Cannabis growth and yields. (Warning, lots of off-topic trolls in that thread: https://www.icmag.com/ic/showthread.php?t=295164)

 

[Beta Test Team]

You're wecome. The umol you use depends strongly upon the photoperiod you want to use

I've come to the conclusion that lower intensity creates better flowers. I've also realized that to get the same DLI with less intensity you need longer photoperiod, I've pushed it to 13/11.

Yes, exactly. See this study (http://www.gwpharm.com/uploads/finalfullthesisdjpotter.pdf) if you haven't yet read it. And while it's flawed, it's also quite useful and interesting. Note that "PAR watt" is energy from the lamp as W/meter sq. within 400-700 nm, not input power (wattage) of the lamp per area.

The reason I suggest higher umol (often defined as PPF) in flowering is to increase DLI in flowering due to the loss of photoperiod. And the reverse is true for veg, where Gavita's suggestion of 1,000 PPF (umol) is just way too much for an 18 hour photoperiod (let alone 24 hours).

I also use greater than 12 hour photoperiod, normally max is 13 hours. The effect on plant growth and yield is pretty great, though it does increase flowering time in my experience.

For those reading that want to know how to find DLI, here: (umol)*(photoperiod)*(0.0036)

So in layman's terms, use bigger footprints, raise the lights, and run longer lights on during flower. An added benefit is yield increases.

I like to start with the DLI I wish to achieve, then work backwards for each growth phase, knowing the target umol range and photoperiod. That way one can dial in fixture placement and distance to achieve the calculated umol to achieve the desired DLI.

To your list I would add, increase fixture density while not exceeding the goal umol (not as an averaged umol over area) to increase radiation uniformity (which leads to better growth and yields).

 

[TheArchitect]

architect,when you do the 13/11 how does it effect overall flower times? not sure it would make them decrease because increase in production time or increase because they wouldn't have that "rush to finish" push that a 12/12 gives them...

TheArchitect - 13/11 - you got me interested.. what lighting plan works best for this altered times? and what umols are you shooting for, if you have this numbers?

thank you

Contrary to betas experience, I actually experienced shorter flower times, marginal, maybe 3 days. Can't say for sure why, but likely the increase in DLI without the increased intensity.

https://www.google.com/url?sa=t&source=web&rct=j&ei=olLeVL28IoSUyQS4rYCgCA&url=http://flor.hrt.msu.edu/assets/Uploads/DLI-and-annuals.pdf&ved=0CC4QFjAE&usg=AFQjCNFyrF0g9R9qygQg1I5EHGCEi-H4ig&sig2=K6A870eLhDCRhYbOUAvpUQ

Flowering Time
In all of the crops studied, time to
flower decreased as DLI increased.

Thanks for the conversation beta, and all, I've been wanting to talk about this for a while, had planned on starting a thread, but wanted more experience first.

 

[plumbum]

where Gavita's suggestion of 1,000 PPF (umol) is just way too much for an 18 hour photoperiod (let alone 24 hours).

while I am still reading your previous post…

this is straight from Gavita as far as PPFD goes:

 

[Beta Test Team]

Thanks, plumbum. Not sure if they changed that recently, I thought they were suggesting 1,000 PPF for veg and flowering. I agree with their targets now, though I'd say veg is a little to low and flowering a little to high (when considering the +/- umol from the targets that will occur).

If stating a single value as the target, I'd say 500 for mothers, 800 for veg (17 to 18 hours), and 900 for flowering (12 to 13 hours).

 

[Beta Test Team]

Contrary to betas experience, I actually experienced shorter flower times, marginal, maybe 3 days. Can't say for sure why, but likely the increase in DLI without the increased intensity.

https://www.google.com/url?sa=t&sou...gQg1I5EHGCEi-H4ig&sig2=K6A870eLhDCRhYbOUAvpUQ

Thanks for the conversation beta, and all, I've been wanting to talk about this for a while, had planned on starting a thread, but wanted more experience first.

Ditto. And about the flowering time, I think this depends upon other factors as well, including (but not limited to) umol intensity (like you suggested), genotype, and average daily temperature. I notice an increase of a few days, generally.

 

[divine moments]

I'm not going to move just so I can grow, that would be idiotic

No but if you've been arrested 22x for marijuana in 32 years, thats idiotic.

 

[whazzup]

I wouldn't take Gavita's word on it. Best thing to do: buy a few fixtures and install them in a few different scaled-down mock-ups of your room, and using your quantum sensor dial in both the uniformity (lower difference between high and low umol per area) and the umol.

With all due respect beta test team.... We have been making light calculations based on photogoniometer based certified electronic models for quite a few years now. In horticulture we need to guarantee light levels and uniformity, and they are pretty accurate.

I suppose you suggest a 5x5 right? It is impossible and really bad advice to tell people to dial it in with a quantum meter. Impossible. If you see how long it takes us to make a calculation and get it right, and we only have to move the fixtures in our models, not in real life.

This is really bad advice.

 

[whazzup]

Yes, 1,000 umol is too much (especially per day), and the way Gavita measures that umol is also not correct, or, should I say, not the 'whole picture'; it's not the average of umol over 3'x3' that matters, but the umol per much smaller area, this is about uniformity, which Gavita severely lacks.

For example, to reach 1,000 umol average, there will be spots on the canopy with well above 1,200, up to 1,500 umol, as well as spots that are well below 600 umol, down to 200 or 300 umol.

If your number of fixtures isn't important, and you really want to use Gavita, I would pack them in and dim them to somewhere between 60% and 80%. That way you can reach a target umol (like 800, or 1,000 if you wish) while also having better uniformity than you would if running Gavita's at 100% and using fewer of them.

Oh yea, without a quantum sensor (https://www.icmag.com/ic/showthread.php?t=298086) you really can't be sure what umol you're providing. You can't go by Gavita's suggestions because each room is different in terms of various factors affecting radiation.

https://www.icmag.com/ic/showthread.php?t=297147
https://www.icmag.com/ic/showpost.php?p=6789995&postcount=10
https://www.icmag.com/ic/showpost.php?p=6790112&postcount=12

Beta test team I am sorry but you are very wrong. When we say 1000 umol we mean 1000 umol ppfd over the canopy with a uniformity of 90 percent at least. We do not get hot spots in our light plans.

Who says we measure over a 3x3? That is ridiculous. This grid tests are totally bonkers. They prove that a deep reflector will give you more light under the reflector, nothing else. We do not use grid tests and we definitely do not recommend to hang our lamps in square 5x5 grids.

Secondly your advice to run them dimmed totally discredits you completely. If you were informed you would know that the efficiency will drop when you dim a lamp. Haven't you read this thread at all?

 

[whazzup]

I see members having problems running the lamps at 3 ft at 1000W. You can indeed have problems if you do not position them correctly: in the overlap you will have too high light levels. That is why it is important to position them correctly. In his thread I have given you guidelines, if you have a large room then we can make you a light calculation. A HPS lamp NEVER will give you a square field. It is always wide and rectangular. Forget the 5x5 please.

1000 umol ppfd is for experienced growers optimal as in optimal yield from the space available. If you are not an experienced grower I would not suggest that you run at these intensities, you need to have a firm grip on your crop to pull that off. You will be giving your plants a dli of 43 null at 1000 umol per 12 hours! That is why you should also dim to about 660 umol in a 18 hours veg cycle, that will result in exactly the same dli. Don't forget plants are photon counters. It is the number of photons that define photosynthesis, in a spectrum that is favorable for plant growth.

A gram per watt is not an illusion. We have reposts of people getting 3lbs per light. But if you are a novice grower you should start at lower levels. More like 700 umol m-2 s-1. Actually with more space and a lower intensity you will get a better yield. However, if you want to optimize your yield a high intensity over the space available will give you the best return on investment.

As you might have seen I can no longer be active on the forums, I just do not he e the time any more. I regret that, but I have given it my best. Once in a while I will drop by though, but if you want support please open a ticket on our website.

We have the honor btw of being the most imitated product in the history of hydroponics

Thank you all for your support.

 

[Beta Test Team]

I wouldn't take Gavita's word on it. Best thing to do: buy a few fixtures and install them in a few different scaled-down mock-ups of your room, and using your quantum sensor dial in both the uniformity (lower difference between high and low umol per area) and the umol.

With all due respect beta test team.... We have been making light calculations based on photogoniometer based certified electronic models for quite a few years now. In horticulture we need to guarantee light levels and uniformity, and they are pretty accurate.

I didn't claim otherwise. What I claimed (and is true), is the room and growing method has a lot to do with ideal fixture placement as it relates to uniformity over all areas of the canopy. A one-size-fits-all approach doesn't work.

And I've used our quantum sensors in rooms of growers that followed Gavita's fixture placement advice (as well as ePapillion's), and the results are never what the growers expected, at all (in terms of min, max, and averages). I'll just leave it at that...

I suppose you suggest a 5x5 right? It is impossible and really bad advice to tell people to dial it in with a quantum meter. Impossible. If you see how long it takes us to make a calculation and get it right, and we only have to move the fixtures in our models, not in real life.

This is really bad advice.

No, I don't suggest 5'x5', that's very poor spacing.

It's not impossible to use a quantum sensor to optimize fixture placement, far from impossible. In fact, it's the only truly accurate method of fixture placement, because computer modeling is only that: modeling (not real world measurements).

I know a lot about this topic of computer modeling for optimized fixture placement as it relates to irradiance and uniformity. We have spent thousands of dollars on modeling through LIT Optics (for Greenbeams).