# Cool toy on Buildmyled.com



## Jeffww (Aug 6, 2010)

What's the point of knowing through-air par. We already have a decent idea of what the PAR on most bulbs should be without water. It's harder to work with underwater stuff.


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## Build My LED (Nov 24, 2012)

Veryzer. Glad you think this is helpful  We are currently working on the under-water measurements, but the air measurements allow us to predict average PPFD (PAR) measurements for the specific tank size. Beam angles will narrow in the water, but the total amount of the light in the tank will not be impacted beyond the Fresnel reflections off the top of the water.


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## dastowers (Feb 19, 2011)

Nick, I love my three lights. The plants are growing like weeds!


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## Steve001 (Feb 26, 2011)

dastowers said:


> Nick, I love my three lights. The plants are growing like weeds!


In the other thread didn't you promise us some pics ? If you didn't I sure would like too see some please.


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## dastowers (Feb 19, 2011)

I did and posted them.  love these lights and have posted them on at least two sites. But...have to make sure it was here too. Lol!!


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## Steve001 (Feb 26, 2011)

dastowers said:


> I did and posted them.  love these lights and have posted them on at least two sites. But...have to make sure it was here too. Lol!!


Can't wait to see, but I guess I have too. :icon_wink


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## dastowers (Feb 19, 2011)

Here they are (low quality iPhone 4s pics): Installation day 12/11/12 ***Note I was only using EXCEL and Flourish during the time span of these photos.*** So I can safely say if you want only a low-tech tank and lush growth- these lights work very well for that too! Actually I harvested the plants from this tank TWICE during the three weeks and lightly planted a 75 gallon bowfront and heavily planted 42 gallon bowfront (which has these lights also). The Amazon Sword mother plant (left corner) has been very generous also- lots of babies. They were out of control- in a good way. LOL!

Yesterday -I installed the Ultimate CO2 system from GLA and started EI ferts. Will start a journal soon so I can see the progress. 










Lotus 3 weeks ago when lights installed:









Picture taken today 3 weeks later. Notice the growth on the Lotus especially:


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## dastowers (Feb 19, 2011)




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## Steve001 (Feb 26, 2011)

Very nice colors showing. What is the CRI of this lighting ? What leds did you use ?


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## dastowers (Feb 19, 2011)

Used the stock lights. 2 - 48 inch lights over a 6 foot tank 150 gallon tank - suspended 8 inches above.

Copied these specs off the site: Freshwater Show Tank

http://www.buildmyled.com/freshwater-show-tank/

Commercial-grade, IP66 Waterproof LED light fixture assembled with a custom spectrum developed specifically to highlight all of the colors a freshwater show tank. By using a mix of the world's most efficient LEDs, these fixtures deliver incredible PAR levels (micromoles/m2/s) into your tank. Hence, this spectrum is extremely capable of growing the most demanding freshwater plants. The slim fixture design (1" tall / 2" wide) will improve the appearance of any aquarium. Available in 4 fixture lengths and 5 beam angles to work with all aquariums. For those seeking less pink in the light spectrum, this is a great alternative to the Freshwater Planted Spectrum. See the product comparison video link under the image thumbnails (lower left).

Product Specifications (PDF Spec Sheet)
- Lumens: 12" Fixture = 1,220 / 48" Fixture = 4,878
- Micromoles: 12" Fixture = 21 / 48" Fixture = 85
- Input Watts: 12" Fixture = 19W / 48" Fixture = 75W
- Input Voltage: 90-305 VAC
- Color Temperature (CCT): 12900K
- Color Rending Index (CRI): 86
- Operating Temperature : -20C to 45C
- Predicted Life: 50,000 Hours
- LED Selections per 12" Board:
(10) 5700K, (2) 470nm, (1) 660nmm (1) 525nm, (1) 450nm
- Spectral Content (Photon Count):
38% Blue, 36% Green, 24% Red, 2% Far Red

Product Features
- 0-10V Dimming Compatible Driver (Apex Ready)
- IP66 Waterproof Rating
- CE Safety Certification & ROHS Compliant
- Built-to-Order in the USA
- 3 Year Warranty
- Innovative 'T-Rail' for Unlimited Mounting Options
- Return within 30 Days for Full Refund
- System Includes:
LED fixture/power supply/8' cord/plug/mounting brackets


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## dastowers (Feb 19, 2011)




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## -Az- (Jan 2, 2013)

Build My LED said:


> Veryzer. Glad you think this is helpful  We are currently working on the under-water measurements, but the air measurements allow us to predict average PPFD (PAR) measurements for the specific tank size. Beam angles will narrow in the water, but the total amount of the light in the tank will not be impacted beyond the Fresnel reflections off the top of the water.


Nick,
it's great to see someone putting in the effort to give some easy to understand data.

a couple of comments ( I hope they're a help and not a PITA)

while reflection is a major loss of light energy there are a few more factors that impact light through water. there's some quite handy information (graphs, tables, formulas, the lot) out there from oceanology studies and even industry probe/sensor setups (eg ultrasonics - sound is just a different size wavelengths and same laws apply)

http://scholarsarchive.library.oreg...ASAbsorptionAttenuationVisible.pdf?sequence=1

Reflection & Refraction - lower angle of incence means more light will pass into the water.
using fresnel and snell you can determine how much energy has been reflected & how much has passed through & at what angle.
unfortunately these laws only apply for plane waves with a constant frequency.

Absorbtion - light becomes heat or is used in photosynthesis. this is what gives water colour. water appears blue as the blue photos travel futherest before being absorbed. after 1m 60% of all the light energy has been absorbed (as red photons only travel 1m all red has been removed after 1m)
absorption will decrease as temperature increases. salinity is also a fat or.

Scattering - light photons change direction ( often upwards)
as pure water scatters very little it appears dark ( light is absorbed) turbid water on the other hand reflects (scatters upwards) and appears lighter
2 forms of scattering are; 
molecular (short wavelengths scatter more than long. the sky appears blue as blue is scattered first)
particle (wavelengths scatter equally (clouds appear white as the light is scattered equally)

well my 2 bobs worth
hope it makes sense


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## dastowers (Feb 19, 2011)

Not sure if anyone is following this but here is 24 hours later. The curled leaf has grown into the one in front of the largest red discus. Amazing.


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## Rapt (Jan 5, 2013)

*Red Lotus*



dastowers said:


> Not sure if anyone is following this but here is 24 hours later. The curled leaf has grown into the one in front of the largest red discus. Amazing.


Just wanted to comment on growing the red lotus. 
As you may be aware this is a tropical water lily rather than a true lotus. These plants can grow very quickly and very large with the right conditions. This one plant could cover half the surface of the tank in a few weeks

These plants will take very high levels of fertilization. When I was growing water lillies all the time they would get 1-3 plant tabs depending on plant size around/in the root ball once a week and grow madly. I often used Jobes tomato spikes for this. I was growing outdoors in ponds and tubs and indoors in a 4'x8' pond. For good blooming once the plant is mature a high P level fertilizer (say 8-24-8 and long wavelength (orange-red light ) will encourage good blooming. Plants don't respond terribly well to lots of blue light in terms of growth.


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## dastowers (Feb 19, 2011)

Rapt..Thank very much for the info! Good to know-this plant has really exploded with the ferts so I figured it was a really heavy user. Planned on trimming the one directly as it has sent up quite a few floating leaves and don't want it to shade my foreground plants.


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## Simpsoid (Jun 26, 2012)

Your tank looks great dastowers.

Could you tell me what the plant in the first picture of post #9 is? It's the plant in the bottom right corner with the very red colouring under the leaves. Thanks!


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