How much is too much?

[HayStack]

Since moving to a 4x4 tent. I'm trying to figure out what the best lighting would be. At first I had two LED's. One is a GlaxyHydro 300 watt and the other is a ViparSpectra PAR 600 watt. They were in the center of the tent. The GalxyHydro in the front and the ViparSpectra in the back. The only problem with the two lights, was that it seemed a bit dim on the outer edges of the tent. So, I just added a KingPlus 1000 watt on the left side and pushed the other two a little to the right. I doubt that any of the lights I have put out the true stated wattage. But all together they come to 1900 watts. But there seems to be no more dim areas at the edges.

Is this overkill and will I just end up burning the plants? To me it doesn't look too bright. But I'm still new at this and really don't want to end up with a couple of dead plants.

Whadaya think?

 

[Scientific]

Hi HS -- As you probably know, the wattage on the box is the maximum rated wattage of the LEDs. The specifications or the Amazon page usually has the actual watts used or amps drawn somewhere, and it's usually about half the number on the box.

So figure your "1900 watt" setup is actually half that, 950 watts. Even though purists hate it, watts per foot is a good starting point for calculations. 950 watts over 16 square feet gives 60 watts per square foot, which sounds great. Sweet Sue just completed a grow in a 2x2 tent with an LED Grow light that used 85 actual watts and got acceptable results with just 1/3 that many watts per foot.

The only potential problem that I can think of is hot spot under the center of LED grow lights. They don't spread their light as evenly as I'd like, so the center of the footprint can be ground zero. Probably the best test of your new setup would be to closely watch the plant directly below the 1000 watt unit and hoist that light up if you start to see light damage (or turn off some of the diodes if that's an option). But it looks to me like you should be able to grow some big, potent plants with your setup. I would be curious to know how it does if you'd care to post an update.

 

[HayStack]

Thanks for the info. I figured the true wattage was somewhere around your number. I looked at them this morning and they are doing great with the additional lighting. And the entire tent is lit up all the way to the edges of the tent now. Hopefully it helps.

 

[GodOfPot]

I don't think "too much light" could be measured by watts anyways...PPFD Graphs and Analysis for Mars, Amare, Fluence LEDs & CMH this thread here suggests that 1500 PPFD is the top end on Sativas.....and anything beyond that would be wasted...it also suggests that 800 PPFD would be the most "optimal" or "efficient"

I'll be running a true 1260 w in my next grow(overkill for sure) in a 4x4...to give you an idea, looking into your lights it looks like you're drawing a true 665w or so from the wall combined with all 3...the 2 units I'll be running have great heat control(heat sinks + fans, most of the heat is dispersed through the side vents) but still 1260w is a lot of heat in a 4x4...so we'll see soon haha

 

[Scientific]

I don't think "too much light" could be measured by watts anyways...

I did say that the purists would object. I used to work with an aeronautical engineer who felt he couldn't work on a design for a model airplane for his son because he didn't have access to a wind tunnel. This feels similar.

Watts/square foot isn't the ideal measure, but it's an adequate first approximation for those who don't have a $200 meter in their toolbox. We're talking back of the envelope here, not industrial lighting design consultations.

GOP: I'm curious. Do you have a PAR meter? A lux meter?

 

[GodOfPot]

Not by any means a purist...nor did I object....simply stated an answer..."How much is too much?" can't be answered with watts

I own a PAR meter yes, a LUX meter has no use....the only meter I want that I haven't purchased is a UV meter.

 

[Scientific]

a LUX meter has no use...

A lux meter works fine for white (and white-ish) light.

The perfect is the enemy of the good.

 

[GodOfPot]

You seem like the type of friend who would hand your buddy a drill when he's asking for a hammer and tell him just to use it anyways and stop complaining...using a PAR meter isn't about being perfect, it's about using the right tool for the job...

 

[Scientific]

Again, I did say that the purists would object.

 

[Grassmaster]

What you really need is a PAR meter. I bought one for about $150 on Ebay. Should be about 200 -300 micromoles in veg. And up to about 900 micro moles in late flower. But light required for particular strains vary.

With blurpal lights you might not want to use a LUX or Foot Candle meter but even if they aren't accurate they will still work as a reference point .

 

[HayStack]

Well the good news is that the plants seem to be thriving with the additional lighting. In just five days, there is a very noticeable difference.

 

[Grassmaster]

I looked the units up. Galaxy 300 is 140 actual watts (at $86.99). Viparspectra 600 is 285 actual watts (at $224). And the King 1000 is 185 watts (at $112). So a total of 610 watts at just $422.99.
If is works and grows satisfactory plants that's all that matters. You could buy a better light that would do the whole tent like a Perfect Sun Goliath that would use only 570 watts Black Diamond LED grow lights Perfect Sun.Or a Spectrum King 400 plus. They would likely do a better job but they would cost more.

 

[LB07]

I looked the units up. Galaxy 300 is 140 actual watts (at $86.99). Viparspectra 600 is 285 actual watts (at $224). And the King 1000 is 185 watts (at $112). So a total of 610 watts at just $422.99.
If is works and grows satisfactory plants that's all that matters. You could buy a better light that would do the whole tent like a Perfect Sun Goliath that would use only 570 watts Black Diamond LED grow lights Perfect Sun.Or a Spectrum King 400 plus. They would likely do a better job but they would cost more.

I'd skip buying a unit and build one! Solid advice though.

 

[HayStack]

I looked the units up. Galaxy 300 is 140 actual watts (at $86.99). Viparspectra 600 is 285 actual watts (at $224). And the King 1000 is 185 watts (at $112). So a total of 610 watts at just $422.99.
If is works and grows satisfactory plants that's all that matters. You could buy a better light that would do the whole tent like a Perfect Sun Goliath that would use only 570 watts Black Diamond LED grow lights Perfect Sun.Or a Spectrum King 400 plus. They would likely do a better job but they would cost more.

Thanks for the info. I may at some point buy another light. But at the moment this grow is going really well and I think it will be fine for this go round. But I did make one change since I made this thread. The Galaxy 300 has been replaced by a Bestva 1000 watt unit. And it also draws just 185 watts. I'm pretty sure it the exact same light as the King Plus, just a different color.

 

[Techman]

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[HayStack]

First of all. Thanks to everyone who has helped me so far. But Now I'm asking for a little more help. In the last few days the tops of one of the plants has started to yellow a little bit and I'm not sure why. The only thing that has changed is the lighting. Back on the 15th I removed the Galaxy 300 and replaced it with a BestVa 1000. But the BestVa light is on the other side of the tent above the other plant which seems to be doing fine. Nothing has changed with my nutrients, but the plant on the left is yellowing just at the tops. The rest of the plant seems to be fine.

Could this be from the additional lighting? Or could it be a ph problem?

I have never done anything with ph on any of my grows, and this is the first one with yellowing tops.

This is a closeup from this morning

This one is the full top from this morning.

This one is a closeup from Monday morning. You can see that is has no yellowing

This one is the full top from Monday morning.

And once again. Any help is greatly appreciated.

 

[GodOfPot]

Super hard to tell with pink light....won't be a result of the additional light though...def something else at play .

 

[HayStack]

Super hard to tell with pink light....won’t be a result of the additional light though...def something else at play .

I agree. I think it's either a calmag problem. Or it could be a ph problem. I have never checked ph when I water. But I've never needs to because I've had several grows and never had a ph problem before.

 

[SamSmith]

The plants look funny under leds especially if you cant cut the purple out of them such as a veg/bloom switch. You have to get them out of the tent or turn the light off and use a normal spectrum source.

 

[SweeetExide]

Top of a plant being affected means immobile nutrients if there is no sign of excess feeding
yelling from the base of leaves outwards to the tip ?
excess phosphorous mimics the symptoms of an iron deficiency, yellowing at leaf base first and spreading to tip.
however you will see nutrient burn at the leaf tips if excess Phosphates
could be over watering or lack of immobile nutrients, I'd try flushing with a mild nutrient solution next watering.
make sure to let those big pots dry out well in between watering