## What do you think of the comparrison?

• ### It stinks...change the water

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#### Kobey

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So I am trying to finalize my lighting choice for a 33-gallon Long (48x12x13h).

(It's a low tech natural planted 2" substrate with tannin colored water from Indian almond leaves and a glass lid for reference)

But after reading a colossal amount of stuff on light and lightening and then looking at the specifics of these lights I am looking for some input in what I think I have come up with.

Now price is always a factor but I'm ignoring it because it's only a factor for us as individuals and we can do that after everything else.

Let me start off with the specifics of the Finnex Stingray lights from their site:

48" 56x 7k white leds, 8-red, 8-blue
36" 40x 7k white, 8-red, 8-blue
30" 32x 7k white, 8-red, 8-blue
24" 27x 7k white, 5-red, 4-blue
20" 23x 7k white, 5-red, 4-blue
16" 20x 7k white, 4-red, 4-blue
12" 12x 7k white, 3-red, 3-blue

So looking at the white leds first what I did was figure out the comparative white lighting based on a per inch of fixture.

48" @ 56x7000 = 392,000 / 48 = 8,167k per inch
36" @ 40x7000 = 280,000 / 36 = 7,778k per inch
30" @ 32x7000 = 224,000 / 30 = 7,467k per inch
24" @ 27x7000 = 189,000 / 24 = 7,875k per inch
20" @ 23x7000 = 161,000 / 20 = 8,050k per inch
16" @ 20x7000 = 140,000 / 16 = 8,750k per inch
12" @ 12x7000 = 84,000 / 12 = 7,000k per inch

Now that's less then half the puzzle but it's solid start. Next I added in the comparative amount of red and blue leds. (Now I know this gets complicated because of things like red light depth penetration verse blue light and the equivalent kelvin of each to produce a overall PAR...never mind PUR), But keeping it overly simplified if we just compare the total number of leds to the % of red and blue it highlights more then I would have thought.

48" @ 72 leds with 8-red & 8-blue = 22.2% of leds R+B
36" @ 56 leds with 8-red & 8-blue = 28.6% of leds R+B
30" @ 48 leds, 8-red, 8-blue = 33.3% of leds R+B
24" @ 36 leds, 5-red, 4-blue = 25% of leds R+B
20" @ 32 leds, 5-red, 4-blue = 28.1% of leds R+B
16" @ 28 leds, 4-red, 4-blue = 28.6% of leds R+B
12" @ 18 leds, 3-red, 3-blue = 33.3% of leds R+B

Now with both these basic sets of comparisons it should become obvious why that Finnex PAR diagram we've all seen showing a graduated depth of 24" cannot really accurate for anything other then the specific light for the demo tank it was used on (if that).

Also it seems that that best combination of Red to Blue light for proper wavelength leds is 2-1...so ideally you want 2x as many red leds as you do blue...and both of those should be less than 1/3 combined of your total Kelvin. We can discount that for this comparison simply because we are dealing with set fixtures.

But for those of us trying to do a "best guess" as to what actually works this is a summary I think will help.

48" has 8,166k per inch white and 22.2% Red + Blue component
36" has 7,778k per inch white and 28.6% R+B component
30" has 7,467k per inch white and 33.3% R+B
24" has 7,875k per inch white and 25% R+B
20" has 8,050k per inch and 28.1% R+B
16" has 8,750k per inch and 28.6% R+B
12" has 7,000k per inch and 33.3% R+B

So looking at that the 16" will push a lot more light down deep compared to a 12"...in fact the 16" will push more light down then all the others.

The 12" at only 7k and with 33% R+B means it is going to be a much "warmer" light compared to the "colder" light of the 48" with only 22% R+B.

Now in my specific case I'm trying to light a 48x12x13h natural low-tech planted tank (33-Long). What most would say is pretty easy drop a 48" fixture on it...except now looking at what I just summarized there are 3 very different options.

(1x) 48" @ 8,166k per inch white and 22.2% Red + Blue
(2x) 24" @ 7,875k per inch white and 25% R+B
(4x) 12" @ 7,000k per inch and 33.3% R+B

The answer to deeper tanks has always been to push more K and even Blue to get the light down there but when it comes to shallower tanks (10g, longs, breeders) that extra light is not what you want (ignoring CO2).

And again cost aside there is one other added benefit to running multiple lights like these on shallower tanks. You can space the timers 1-hour apart with 11-hour "on" giving you 1hr morning, 10-both, 1-hour evening cycles.

For me...I think I'm going to go with 2x 24" because I'm a tad worried 33% R+B is overkill and I will take those 2 extra red leds instead of whites in the 48"

As for my basic guide to Finnex Stingrays...what do you think?

#### Kobey

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Low tech, what plants? Stingray if easy mode like mosses. 24/7 if red plants and others.
Plants: Elodea, Watersprite, Anubias nana, Dwarf Sag, Java Moss, Crypt Wendtii, Java Fern, Red Ludwigia.

The 24/7 is wicked powerful for a 12" to substrate depth even with CO2 I was told.

#### Kobey

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I know enough to know I cannot properly speak to the quality or quantity of red leds in regards to nanometer differences...or blues for that matter lol.

I think they general thought in regards to the red though (and I could be completely mistaken) was that with so much of the red light not reaching depth increasing that over say blue or white has arguably more value. Even more so with those using glass tops.

It's why I sort of glossed over it and lumped the total red and blue together compared to total white. Also the stingray is the weakest of the bunch though I would imagine that a comparison of the Fuge or Planted or 24/7 based on the same numbers in their respective classes should technically work in that it would illustrate a relative value. Sort of like how "in air" verse "in water" PAR values are different but as long as they are not compared to each other they are still on par with similar readings.

Though I also admit I'm very new to this and hitting it from a analytics instead of practical background.

In your specific case though if the reds are in actuality increasing par would you not be better to raise a 24" light with fewer reds to give you the coverage you need?

#### Kobey

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So just as a quick follow up to what i originally wrote:

I have learned a great deal about lighting spectrums (maybe enough to claim intermediate understanding lol).

And everything aside this comparison of Stingray models does actually point out some issues most other lights do not have.

Mainly each light composition differs depending on the length of the fixture.

Most manufactures will simply repeat a LED pattern over length but here we end up with 7 fairly different models, and things like 25% more daylight or 13% more red/blue LEDs really change and confuses everything.

So in short my comparison might be unorthodox and it ONLY works for these lights. But it is surprisingly accurate for the limited scope of what it is.

(I'm actually thinking Finnex made 7-different lights to see which worked best in the real world lol)

Still for the price they are; those differences are by no means a show stopper in any respect.

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