NukaKola
Well-Known Member
30w per sq ft. which is a general baseline for LED lights.
4x4 = 16sq ft x 30w/sq ft = 480w
Dimming
- Thread starter Wabbles
- Start date
4x4 = 16sq ft x 30w/sq ft = 480w
Boatguy
Well-Known Member
Hlg advertises their their 550 for a 4x5, and timber advertises its 640w fatty for a 4x4, so it varies depending on light manufacturer. Anywhere in that ballpark would work
Barristan Whitebeard
Well-Known Member
That meter would go in between the plug and the driver on the input side.
If the OP wants to see the drivers output they would want a DC meter (or a multimeter can be used to check voltage, current and such). The meters with built in shunts are easier to wire than the shunts that need to be wired in, especially for novices.
Boatguy
Well-Known Member
Why would it matter which side you measure off? Light wattage can be seen on either side of the driver
TintEastwood
Well-Known Member
Thanks for the info and catching my mistake.
This DC type is what I'm actually using.
DC Power Monitor, DROK Digital Multimeter DC 6.5-100V 20A Voltage Amperage Power Energy Meter, Volt Amp Tester Gauge LCD Digital Display with Built-in Shunt: Amazon.com: Tools & Home Improvement
DC Power Monitor, DROK Digital Multimeter DC 6.5-100V 20A Voltage Amperage Power Energy Meter, Volt Amp Tester Gauge LCD Digital Display with Built-in Shunt: Amazon.com: Tools & Home Improvement
www.amazon.com
Barristan Whitebeard
Well-Known Member
Current and voltage figures will be different on the DC side. This can be useful info to have if you don't want to estimate it yourself.
cobshopgrow
Well-Known Member
would guess youre fine orienting on a 480W driver for a 4x4, or 2x 240W drivers..
thats plenty of light, more then you get from a 600W HPS.
thats plenty of light, more then you get from a 600W HPS.
PJ Diaz
Well-Known Member
I dim my LEDs a bit depending on the growth cycle. I have two 240w (they will go higher than that rating) drivers in a 4x4. For the first week of flower, transitioning out of veg I will usually dim down to around 400w total, then ramp up to 450w after the first week, and a week later go up to 480w to 500w. Towards the end of flowering I will sometimes dim down for the last week of flowering. This seems to produce frostier results. I just use a kill-a-watt meter at the wall to check my wattage levels.
youraveragehorticulturist
Well-Known Member
If you're going to break off $850 for an LED light for your 4 x 4 tent, why not spend $200 more and get an LED light suitable for a 5 x 5 space in case you want to upgrade later? In the mean time you can dim it a bunch to veg and dim it less to flower, in your 4 x 4 space.
youraveragehorticulturist
Well-Known Member
It's OK dude, if you don't get it it's totally fine.
Dimming your lights is not mandatory. You never need to if you don't want to.
Dimming your lights is not mandatory. You never need to if you don't want to.
I know it's my choice to dim or not, not the point.
My point is, the majority of posts I see regarding LED fixtures, is people are dimming them to a lower the output, I am just curious why ?
Back in the day, you bought a 1000w HPS/CMH/MH.... because you wanted 1000w's, why is it not the same with LED's ?
I'm just trying to understand, not trying to argue with anyone.
NukaKola
Well-Known Member
I’ve already explained this thoroughly. Even HID growers dim their lights, I know some growers that use Gavitas on controllers to mimic nature. Their 1000w Gavitas will start up at 450w during lights on and gradually ramp up 50w until they reach peak power and then gradually dim down until lights off. For a large room this equates to a good 30% or more electricity savings without any loss in yield or quality.
Say you also happen to grow a strain that stretches more than expected and don’t have tall ceilings. Rather then your buds foxtailing, getting light bleached, or burnt because they are too close to the light and you are not able to raise it any further, you can simply dim the light until harvest.
Dimming has many useful features and practically every light comes with it nowadays.
LED’s are quite powerful and many board style LED’s pack a ton of diodes in a small area which doesn’t give the best spread. Therefore buying 2 boards and dimming them will give much better spread. The same reason many people choose to run 2 315w CMH instead of a 600w HPS, or 2 600w HPS instead of a 1000w HPS.
Prawn Connery
Well-Known Member
So no-one has explained to you yet the relationship between LED power and efficiency. When you dim a LED, it runs cooler and therefore more efficiently. This means, for example, if you halve the amount of power going through the LED, you might only reduce light output by 45% – a 10% efficiency gain (10% more light for the same power).
Keep dimming and you may see even bigger gains. There is often a sweat spot where a LED fixture is not maxed or under-driven but makes a good amount of light for the power draw relative to the light spread and area. But if you dim too much, you may lose efficiency through the driver, so there is another sweet spot depending on how components are matched.
Dimming gives you flexibility. Turn the LED fixture up in winter when you need more warmth, hang the light a bit higher and now the LEDs are less efficient, but produce more heat. Turn the fixture down and hang the LEDs slightly closer in summer to run cooler.
Maintain the correct amount of light throughout a grow with the dimmer instead of raising or lowering the lights.
The correct amount of wattage per square foot depends on the fixture efficiency, the size of the grow area, reflectiveness of walls and ceilings, the type of plant. It could be anywhere from 25-45W/sqft
Get the size that you want to flower at the efficiency you want to run and you can dim it down from there.
Prawn Connery
Well-Known Member
I'm pretty high, so what I'm trying to say is get a fixture that will give you enough power to flower with the option to dim if you wish. It's no different to the old days where you get a 600W HPS for a certain area – you maybe want 350-400W of LED for the same area. It will cover the area better than the HPS, be more efficient and provide a better spectrum. If you want to dim it down from there to veg plants under the same light, then wick it up for flower, you can.
GBAUTO
Well-Known Member
That's a baseline for top-tier diodes.
THAT is how top-tier diodes can generate the same amount of light with less power compared to HID or older tech diodes.
Remember to consider the efficiency of the light source at converting watts of electricity into photons of useable PAR.
haze010
Well-Known Member
Also i will add that the plant strain makes a big difference on how much light they want as well. With 600w of led strips in a 4x4 i was showing signs of light stress and lowered it down closer to that 480watt when running a blueberry kush (heavy indica strain). Same tent, same lights, same nutes, when i run chemdawg (sativa leaning hybrid) it takes all 600watt and still seems to want more.
Grow Lights Australia
Well-Known Member
Yes, we've seen the same phenomenon in mostly indica vs mostly sativa grows. The sativas can handle maybe 1000-1100 PPFD while many indicas will bleach under that and are not happy until you get PPFD down to around 800 or so. The other variable is the LED lights themselves. Somre are better than others.
Grow Lights Australia
Well-Known Member
It can be, but then you need to measure both sides to see how much you are losing to the driver (or compare it to the advertised losses from the datasheet). Plus it's handy to know what sort of DC voltage and current you have at the boards so you can match to future drivers or other boards.