How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Needs

[jummejum]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

just got my lights with the mail one week ago must say i love them compared to my old ufo and the small COB sidelights i had installed. Thanks MarsHydro

Good stuff clownbag Happy growin'

 

[Doozy]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

Word!!

Ok, so it must have been the genetics from Dinafem that ruined my grow, fantastic in veg, but garbage in flower.....because i have 43w per square foot at the plug

Acheived this in veg

This in flower

And yet yeilded less than 0.5gpw at harvest.


If we're all trying to work together to get better results, i'm just wondering why most of us with these lights don't get more tham 0.5 gpw, when HPS gets a standard 1.0 gpw....

I'm not sabotaging this thread....but can we get a balanced view here....isn't this what forums are all about?

 

[Robert Celt]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

Not sure what to tell you Doozy, I have never grown with anything but LEDs. Maybe its the strains you grew maybe something else. I grew Bomb Seed strains and used organic soil that only required watering. I do intend on trying other strains at some point but my next indoor grow will be 4 clones of one of my outdoor THC Bombs that I will mainline and see if I can improve on my results

 

[Icemud]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

Ok, so it must have been the genetics from Dinafem that ruined my grow, fantastic in veg, but garbage in flower.....because i have 43w per square foot at the plug

Acheived this in veg

This in flower

And yet yeilded less than 0.5gpw at harvest.


If we're all trying to work together to get better results, i'm just wondering why most of us with these lights don't get more tham 0.5 gpw, when HPS gets a standard 1.0 gpw....

I'm not sabotaging this thread....but can we get a balanced view here....isn't this what forums are all about?

I believe your lights are too high Doozy. Those 400's should be within 10-14" from the tops of your plants, and by the looks of it they are much higher...

With respect to the original post, lighting should NOT be chosen by wattage as it does not tell how this light is projected across your canopy and has absolutely no relation to how plants use light.

Plant lighting should be chosen by "fluency rate" which is referred to as (PAR, umol, micromoles, PPFD, PPF) and many other terms thrown around. For flowering you should have at least 500 micromoles/m2/s-1 and most growers tend to accept that 800 micromoles/m2/s-1 is ideal. Any more than 1,100 micromoles/m2/s-1 then additional CO2 should be added, and cannabis typically can receive up to around 1500 micromoles/m2/s-1 before it maxes out "light saturation point".

The best way, and way that the research, science and horticulture industries (Big Ag, commercial farms, greenhouses and universities) is by using DLI, or Daily Light Integral, which can be measured by a PAR meter (quantum meter). Cannabis at minimum should at least have a DLI of 22 moles/day but can go up to 65 moles/day which translates to between 500 and 1500 micromoles/meter squared/second.

By requesting a 4x4 grid, with PAR (fluency rate) measurements from a lighting company is the most accurate way to judge plant lighting as plants are photon counters, and the rate of photosynthesis is determined by how many photons are absorbed. When you look at the 4x4 chart for a particular light, you easily can see at what height a light will cover a certain area. What you look for is what area the light will provide at least 500 micromoles/m2/s-1 of photons. For the Mars 400, based on tests with quantum meters, those lights should be hung within 10-15" of the canopy and realistically cover only an area slightly larger than the light itself.

Those Mars 400's put out MAX 608 micromoles/m2/s-1 at DEAD CENTER at 18", which just barely brushes the need for flowering, and only at the direct center of the panel. Move out 6" either way at 18" and you only are getting roughly 320 micromoles/m2/s-1 which is too low for a good yield.

I think that if you moved your lights closer to the plants at MAX distance 15" away or less from the tops of the plants you will get much better results.

 

[Doozy]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

As always Icemud, i appreciate your opinion, but i created a system to drop the light to any height i want using what most people refer to as 'selfie poles'....or monopods.

At flower, the lights were at 22-24" from the canopy.

 

[Icemud]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

Copied fromHO-000-W
Measuring Daily Light Integral in a Greenhouse
Ariana P. Torres and Roberto G. Lopez
Department of Horticulture and Landscape Architecture,
Purdue University
Purdue Department of Horticulture and Landscape Architecture

In commercial greenhouses, several strategies can be used to help properly manage light levels throughout the day and seasonally. Some of the primary reasons why greenhouses manipulate light levels include temperature and irrigation management, photoperiod control, minimizing crop stress, and optimizing photosynthesis.

Supplemental lighting with high-intensity discharge (HID) lamps can increase the light intensity a crop receives and improve and accelerate its growth and development. Retractable shade curtains and whitewash can reduce and scatter light intensity to create a more desirable growing environment during high-light periods. This publication examines the characteristics of green-
house lighting and describes one management option, daily light integral (DLI).

What Is Light and Why Is It Important?
Light is a form of energy called electromagnetic radiation. Electromagnetic radiation, whether from sunlight or HID lamps [e.g., high-pressure sodium lamps (HPS) or metal halide] varies in duration (energy over time), quality (wavelength or color), and intensity (the amount of light at each wavelength or color).We will only focus on photosynthetically active radiation (PAR), which is light with a wavelength between 400 to 700 nm — this also happens to be the light people can perceive. Increasing energy in the PAR range increases plant photosynthesis, (the plant’s most basic metabolic process).

Each crop species has an optimal light intensity that maximizes photosynthesis and plant growth. When there is not enough light, growth and crop quality can decline; and if there is excessive light, photosynthesis and growth will not increase despite the expense of keeping the lights on.

Measuring Light
The most common units for measuring light are the foot-candle (primarily in the United States) and lux (primarily in Europe). It is important for growers to understand the limitations of these units. Both units provide an instantaneous light intensity at the time the reading is taken. As we all know, natural light levels are continuously changing and a single measurement in time does not
accurately represent the amount of light a plant has received in a day. Just as important, foot-candles are “photometric” units based on the amount of visible light detected by the human eye (primarily green light). That means foot-candles are focused on people
and not appropriate for indicating plant photosynthesis. Most horticultural researchers measure instantaneous light in micromoles (μmol) per square meter (m-2) per second (s-1), or: μmol·m-2·s-1 of PAR. This “quantum” unit quantifies the number of photons (individual particles of energy) used in photosynthesis that fall on a square meter (10.8 square feet) every second. However, this light measurement also is an instantaneous reading.

Daily Light Integral
Daily light integral (DLI) is the amount of PAR received each day as a function of light intensity (instantaneous
light: μmol·m-2·s-1) and duration (day). It is expressed as moles of light (mol) per square meter (m-2) per day (d-1), or: mol·m
-2·d-1 (moles per day).

The DLI concept is like a rain gauge. Just as a rain gauge collects the total rain in a particular location over a period of time, so DLI measures the total amount of PAR received in a day. Greenhouse growers can use light meters to measure the number of light photons
that accumulate in a square meter over a 24-hour period. Jim Faust and colleagues at Clemson University have developed maps of monthly outdoor DLI throughout the United States (Figure 1). These maps illustrate how latitude, time of year, length of day (photoperiod), and cloud cover influence DLI and vary from 5 to 60 mol∙m-2∙d-1.

In a greenhouse, values seldom exceed 25 mol∙m-2∙d-1 because of greenhouse glazing materials and superstructure, the season (which affects the sun’s angle), cloud cover, day length (photoperiod), shading, and other greenhouse obstructions, such as hanging baskets.The Importance of DLI in Greenhouse Production DLI is an important variable to measure in every greenhouse because it influences plant growth, development, yield, and quality. For example, DLI can influence the root and shoot growth of seedlings and
cuttings, finish plant quality (characteristics such as branching, flower number and stem thickness), and timing. Commercial growers who routinely monitor and record the DLI received by their crops can easily determine when they need supplemental lighting or retractable shade curtains. This is especially true for growers in northern latitudes where the majority of crops are propagated from December to March and naturally occurring outdoor DLI values are between 5 to 30 mol·m-2·d-1. Furthermore, these values can be 40 to 70 percent
lower because of shading from greenhouse glazing, structures, and hanging baskets. These obstructions can result in an average DLI as low as 1 to 5 mol·m-2·d-1. There are devices that automatically measure and calculate the DLI your greenhouse crops are receiving. One of these is the WatchDog weather station manufactured by Spectrum Technologies (Figure 2). This instrument is portable and should be placed next to your crop to determine the DLI for that particular area. Some models can be connected to download
data automatically to a computer

Another method to measure DLI is to use a light quantum sensor connected to a data logger or computer (Figure 3). The sensor measures instantaneous light intensity (preferably in μmol.m-2.s-1) at some defined interval (such as once every 15 to 60 seconds),
which allows you to calculate DLI. Table 1 on page 4 provides DLI calculations based on average hourly foot-candles or μmol·m-2·s-1
of PAR measurements. No matter which sensors you use, it is important to keep all light sensors level and clean to assure accurate readings.

DLI Recommendations
Plants grown under light-limiting conditions (a low DLI), typically have delayed growth and development. Research conducted at Michigan State University indicated that maintaining a DLI between 4 to 11 mol·m-2·d-1 during stage 2 (callusing) and stage 3
(root development) accelerates propagation of petunia and New Guinea impatiens cuttings (Figure 4). Experiments with these petunias and New Guinea impatiens have shown that, as propagation DLI increases, rooting, biomass accumulation (root and shoot growth), and quality (reduced stem elongation) generally increase, while subsequent time to flower generally decreases. Similarly, experiments with
seedlings of celosia, impatiens, salvia, marigold, and viola showed that quality parameters at transplant increased when DLI increased up to 12 mol·m-2·d-1.

Based on this research, we recommend that greenhouse growers provide a minimum of 10 to 12 mol·m-2·d-1 of light during the finish stage to produce many shade-intolerant floriculture crops. But remember, DLI requirements differ between greenhouse crops as outlined in Table 2 on pages 5-7. Some growers separate their floriculture crops by DLI requirements. Crops with a DLI requirement of 3 to 6 mol·m-2·d-1 are considered low-light crops, 6 to 12 mol·m-2·d-1 are medium-light crops, 12 to 18 mol·m-2·d-1 are high-light crops, and those requiring more than 18 mol·m-2·d-1 are considered very high light crops.


Convert PAR to DLI.
Do this by using the following equation:
PAR (μmol.m-2.s-1) x 0.0864 = DLI

The 0.0864 factor is the total number of seconds in a day divided by 1,000,000

 

[Icemud]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

As always Icemud, i appreciate your opinion, but i created a system to drop the light to any height i want using what most people refer to as 'selfie poles'....or monopods.

At flower, the lights were at 22-24" from the canopy.

Very cool way to hang the lights

I would highly suggest on your next run moving the lights to no further than 15".

 

[Doozy]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

My lights were, at no stage, any less than 18" from the canopy. During flower they were at 22- 24'.

 

[UncleCannabis]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

Doozy,
As you probably know there are several factors than can effect overall yields such as age and size of a plant when flowering is forced, genetic potential of a MJ genotype and phenotype, amount of light provided, growing methods, nutrient levels, watering schedules, temperatures and humidity, pest and diseases, etc.

It does appear that your lights may have been set higher than what would have been optimum and I do agree with the advise that others have mentioned. Lowering your lights to 14" to 18" above the canopy during bloom will allow for increased photosynthesis and increased yields.

On another note, if it's possible that you harvested prematurely before bud swell then this could also result in lower than expected yields.

By the way, nice set up you've got there. Really nice!

 

[UncleCannabis]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

With respect to the original post, lighting should NOT be chosen by wattage as it does not tell how this light is projected across your canopy and has absolutely no relation to how plants use light.

Icemud is 100% correct. Lighting needs should not be determined by watts per square foot.

The intention of this thread was to provide a simple explanation of how to calculate your grow space size and how to select a Mars II, Reflector, or Sun Series LED for a respective grow space without too much technical jargon that may have confused many.

There were several folks over at the Mars-Hydro thread that could not even figure out the square footage of their grow spaces correctly so a technical explanation of light, the different ways that light can be measured, and plant lighting requirements was never my intention.
Apologies to all for the misleading information.

 

[UncleCannabis]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

My lights were, at no stage, any less than 18" from the canopy. During flower they were at 22- 24'.

This was a little confusing to me. 18" to 24" during flower or 22" to 24"...I wasn't sure. Thanks for clarifying.

 

[UncleCannabis]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

After reading your post (haven't had the time to go through your journal) it appears to me that you've done your homework regarding the setup of your garden and have a really impressive set up.
From this point forward it should just be a matter of tweaking a few things with your grow and you'll certainly be able to achieve 1/2 gram per wall watt with the set up that you have.

As I've suggested previously, it would be most helpful if you would check out some grow journals and youtube videos from folks such as CoFinest and others that are consistently achieving 1 gram per watt and more.

I have never used HPS, only LED so I'm not able to offer up any direct experiences regarding the yield differences that could be expected between an HPS grow and a Mars LED grow.
I've given you the results of my first indoor grow using Mars Sun Series. Unfortunately, that's all that I have to offer in regards to direct experience.

 

[Icemud]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

My lights were, at no stage, any less than 18" from the canopy. During flower they were at 22- 24'.

I answered that your lights are too high, you NEED to lower your lights to 15" away or less.

I also gave the correct way to judge plant lighting...not by watts but by photon count...

22" is TOO FAR from your plants tops, You should have your lights UNDER 15" away...this is why your yield was not as good as you would have liked. You have the proper amount of lights for your garden, but they are not positioned correctly (TOO HIGH) so this is a significant reason that you saw a low yield.

Plants use Photons,
Measuring Photons is the correct way to measure light type and position.
More photons are good
YOUR Lights are too High (your plants need MORE photons)
MOVE lights closer to 15" or less. (from top of plants)
Lights closer = more photons on plants
More photons on plants = higher yield...

You do NOT need to purchase more lights, you NEED to LOWER your lights, They are about 1' too high.

 

[iseckz]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

ice! should i lower my lights then??? they are a good 35" away 480 96x5 reflector

 

[UncleCannabis]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

Since it appears that you are using the light for veg right now the light could be lowered to at least 24" above the canopy of the 3 larger plants.
If you do lower the lights I'd suggest that you drop it down a few inches per day until you reach your desired height setting.

The smaller plants on the left may not be able to handle the increased light intensity just yet. To accommodate for this you should be able to place them away from the center of the light and along the tent wall where light intensity is lowest then gradually move them toward the light as they grow a bit more.
Another option is to place the larger plants on milk crates or something to move them closer the lights while leaving the little ones further away.

FYI - I'm using this same light to veg some young plants and have my light set at 26" above the canopies. They are all doing great.

 

[iseckz]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

I'm flowering actually
I drop it 18" away & left the hps as is.

 

[UncleCannabis]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

You should probably begin gradually lowering the light until you reach about 14" to 18" from the top of the canopy. If you start to notice any signs of leaf stress or bleaching you'll need to raise it back up a bit until they appear to be comfortable.

A good way to tell if you're too close to the plants is to place your hand and forearm at canopy level with palm facing up toward the light and leave your hand there for a minute or so. If the tender skin on your forearm feels hot then your plants will feel the same way. Raise your light a little until you can hold you hand in that position for at least a minute without discomfort due to high heat. (**General rule of thumb that seems to work for many folks.)

 

[UncleCannabis]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

Why light distance is so important.

INVERSE SQUARE LAW -
The Inverse Square Law states that:
The relationship between light emitted from a point source (bulb) and distance are defined by the inverse square law. This law affirms that the intensity of light changes in inverse proportion to the square of the distance.
I = L/D2
Intensity = light output/distance2
For example:
Light Intensity = light output/distance2
100,000 = 100,000/1
25,000 = 100,000/4
11,111 = 100,000/9
6250 = 100,000/16

A 1000-watt standard metal halide emits from 80,000 to 110,000 initial lumens and 65,000 to 88,000 average (mean) lumens. One lumen is equal to the amount of light emitted by one candle that falls on one square foot of surface one foot away. Super halides emit 115,000 initial lumens and 92,000 mean lumens.

A 1000-watt HP sodium emits 140,000 initial lumens, and a 600-watt HP sodium emits 90,000; watt for watt, that's seven percent more lumens than the 1000-watt HPS. Lumens emitted are only part of the equation. Lumens received by the plant are much more important.

Lumens received are measured in watts-per-square-foot or in foot-candles (fc). One foot-candle equals the amount of light that falls on one square foot of surface located one foot away from one candle.

Excerpt From: Jorge Cervantes. "Marijuana Horticulture."

Lumens are not the best way to measure light for horticultural purposes but this excerpt from the book "Marijuana Horticulture" by Jorge Cervantes does demonstrate the importance of light distance and how this affects light levels at the canopy.

 

[Doozy]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

Great stuff

 

[Mars Hydro]

Re: How to Select the Right Mars-Hydro LED Grow Light for Your Specific Gardening Nee

Haha, Uncle, finally show some love to Mars Pro, you love Sun Series, you will love Mars Pro, too. It's like the pro-generation of Sun series. The price will come down. I will keep in touch.

I have 8 Mars-Hydro LED's lights already some of which have not been used yet. Do you think I need some Mars II's also? LOL!

I may order a couple of the Mars Pro's someday when/if the prices goes down.