# 4ft t8 led tubes.



## jeffkrol (Jun 5, 2013)

roughly scales w/ t5 wattage/par










watt/light efficiency is pretty much the same..
In other words.. all things being equal.. 50W of t8 =50W of t5.. AFAICT.
t8's are slightly more efficient.. or were..


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## Khoon2 (Feb 22, 2018)

@jeffkrol thanks. This chart says t8. Are these led or fluorescent. And i am real new to all of this. The red lines are for 2 bulbs HD with reflectors. Leds dont need reflectors since they are directional. Not so?


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## jeffkrol (Jun 5, 2013)

Khoon2 said:


> @*jeffkrol* thanks. This chart says t8. Are these led or fluorescent. And i am real new to all of this. The red lines are for 2 bulbs HD with reflectors. Leds dont need reflectors since they are directional. Not so?


opp's though you were referring to tubes.. My bad!
Never mind then..

But you can assume current LED "tubes" (good ones) are equiv to t8 tubes w/ reflectors..

THAT is THE GOAL of industry..well shooting at t5 tubes too..

selling inferior products at a higher price is usually a losing proposition..but not always..










Lumens are not the whole story...depends where they go..
Then there is current pricing..
https://www.1000bulbs.com/product/2...MIzO7Q-Zq62QIVjYC9Ch29RA5JEAkYASABEgK7B_D_BwE
$393 current price for LEd tubes to match the above specs..
Replacement tubes are not quite "there yet" for the most part.


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## Khoon2 (Feb 22, 2018)

https://www.walmart.com/ip/Yescom-1...e-Replacement-Lamp-Bulb-Milky-Clear/104669279
Hey these are similar to the ones we have available here. Do you then think that 4 of these will be sufficient for a 6 x1.5 x 1.5 tank. With dwarf sag as carpet. No co2


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## jeffkrol (Jun 5, 2013)

Use over 100W of LED's...........and would go more w/ 6'
Unf. more expensive and warmer.. and would need to do DIY 
Keystone KT-LED32T8-72GC-850-D Direct Drive 6' 32W LED T8 5000K


> Integral Driver (Isolated), Eliminates the Need
> for External Driver or Ballast


Regarding 6' retrofits. doubt if you will find "cool white"..but ???
14,000 Lumens 6500k $65 (10)
10,200 Lumens 5000k $134.85 (3)

8,000 Lumens cool white (like 10,000K) $129.95
https://www.amazon.com/dp/B01LFF07EC/ref=twister_B01LFF08QO?_encoding=UTF8&psc=1
NOTE: @ 72" they bow a bit.

yescom makes aquarium lights last I looked.. may find them cheap on "that place"..

sorry really don't like un-fitting lights..personal thing..


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## Khoon2 (Feb 22, 2018)

Thanks


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## jharger (Aug 18, 2006)

I've found this seller on Ebay and have had good luck with there bulbs.
LEDkingDOTus
Also Home Depot has some good bulbs by Toggled if you order online - https://www.homedepot.com/b/Search/...d/Ntt-toggled?Ntx=mode+matchpartialmax&NCNI-5
The bulbs from both these sources are used without a ballast which is more efficient.


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## jeffvmd (Apr 16, 2010)

There are Philips daylight t8/t12 led tubes in home depot that are around $9 per tube. Might be an option as well.


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## Khoon2 (Feb 22, 2018)

@jeffvmd thanks. Do you use these? Are they sufficient lighting to develop a carpet with no co2


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## CFL68 (Feb 26, 2018)

*Aquarium specific 4' T8 LED's?*

Greetings,

Started up my 72 gallon bow front after ~10 year hiatus. Old Co2 injection still working but controller needed new probe. Bought temp controller. Bought a Beamswork DA FSPEC and it didn't seem bright enough so I retrofitted my 48" 3 lamp t8 fixture for direct wire "t8" LED's. I found some 5K/2650 lumen lamps for about 8$ and figured that would give me kablamo well over 12000 lumens. 

FYI - retrofitting t8 fluor to LED is a very quick, easy, and inexpensive process. Just buy non-shunted tombstones for a few bucks and get t8 LED's that support direct wiring and power on one side.

Even though tank was planted, algae became very pronounced. Dialed it back to just one t8 LED plus Beamswork gives me about 7500-8000 lumens. Still too much. Need to adjust timing since I have the lights on way too much.

So a couple questions - 

1. Beamswork is 5200 lumens. How many additional 5K LED tubes (@~2600) would you folks recommend for a high light tank to support hairgrass carpet, etc.? Hours on/off?

2. Are there any aquarium specific 4' t8 LED lamps? The Beamswork is around 10K and it provides nice light. I've googled around but haven't seen much in the >6500K range for t8 LEDs. Most manufacturers go up to 5000K and who knows how accurate they really are...

Thanks. I'll keep reading threads and learning!


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## gus6464 (Dec 19, 2011)

LED tubes are designed to not use the reflectors in a fixture as they don't fire the photons upward. If you have had a fixture with really good reflectors you would see a decrease in PAR going with led tubes.


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## jeffkrol (Jun 5, 2013)

No


Even w/ "perfect" reflectors that could not be the case..


> 28 Watt LED Bulb - 4 Foot T8 Lamp - 3500 Lumens - Replacement or Upgrade for Fluorescent Light


https://www.larsonelectronics.com/p...cement-or-upgrade-for-fluorescent-lights.aspx









no matter how you look at it, you can't get more than 100%...
http://www.lrc.rpi.edu/programs/NLPIP/lightingAnswers/t8/02-t8-light-output.asp




> The 32-watt Sylvania 21999 FO32/741/ECO T8 linear tube features a vivid lumen output of 2,800 while producing a whiter, more natural color for either commercial or residential applications. It has a cool white color temperature of 4100K and an average life of 25,000 hours.


Yea lumens, but in the case of most "whites" fairly comparative..


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## jeffvmd (Apr 16, 2010)

@Khoon2
Have not used them for a tank yet.
Using them as shop lights and seems to be bright.


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## gus6464 (Dec 19, 2011)

jeffkrol said:


> No
> 
> 
> Even w/ "perfect" reflectors that could not be the case..
> ...


There have been tests done on led replacement tubes vs regular ones. At the same lumen output of the bulb if you pop in the tube in a housing with a good quality parabolic reflector the output goes way up. There is a reason why reflector quality accounts for 90% of the output in a T5 fixture. LED tube manufacturers just try to match the output to a naked tube and never take into account the reflector.


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## jeffkrol (Jun 5, 2013)

> At the same lumen output of the bulb if you pop in the tube in a housing with a good quality parabolic reflector the output goes way up.



Physically impossible except for a % of total...
you CANNOT get more total lumens out than lumens in..Photons do NOT reproduce...

Total lumens measured in an integrating sphere is a HARD limit..given identical physical and electrical characteristics..


> The lamps were placed in an integrating sphere at the Lighting Research Center in Troy, New York, and operated using a standard reference ballast circuit as specified by the American National Standard for Lamp Ballasts-Reference Ballasts for Fluorescent Lamps (ANSI C82.3-2002). Electrical measurements were obtained from the reference circuit in the manner specified by the American National Standards Institute (ANSI), while the integrating sphere and an Optronic Laboratories OL 750 spectroradiometer were used to measure the spectral power distribution (SPD) of each lamp.


Any system using it will have losses..NONE will increase lumen output unless you ,say increase current ect.

Would love to see data to the contrary..


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## Khoon2 (Feb 22, 2018)

But most led tubes now are directional. In that the back emits no light. So wouldn't the reflector be in effective. Non the less my question remains. Will 4ft t8 led tubes (4 pcs) be sufficient to grow a carpet of dwarf sag no co2.


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## gus6464 (Dec 19, 2011)

jeffkrol said:


> Physically impossible except for a % of total...
> you CANNOT get more total lumens out than lumens in..Photons do NOT reproduce...
> 
> Total lumens measured in an integrating sphere is a HARD limit..given identical physical and electrical characteristics..
> ...


You kidding right? You take a naked T5 tube and measure PAR. Now take the same tube and pop it in a reflector, PAR goes way up. Take an led tube and a t5 tube both with 2800 lumen output. The naked T5 will put out 2800 lumens without taking into account the reflector. The LED tube will push 2800 lumens with or without the reflector.

Bump:


Khoon2 said:


> But most led tubes now are directional. In that the back emits no light. So wouldn't the reflector be in effective. Non the less my question remains. Will 4ft t8 led tubes (4 pcs) be sufficient to grow a carpet of dwarf sag no co2.


Correct all LED tubes are directional so they do not use the benefits of a reflector unlike regular tubes. Directional output is magnified with regular tubes with the reflector. As for if it is sufficient or not it's had to say without you measuring it.


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## jeffkrol (Jun 5, 2013)

most will radiate at 120 degrees.. A reflector is pointless.. It's sole purpose is to collect and direct light leaving at > 120 degrees, for the most part, and mostly for the "backlight" of tubes.. 

Problem w/ answering your question is few have used t8 LED tubes in other than "shoplight" type fixtures..

But this I can fairly safely, barring getting [email protected] LEd tubes 4 4ft LED's will grow anything 4 4ft. T8's will..

go outside the box...
Prime time for T8 LED lighting?

Can you grow it w/ 2 4' T5ho's?..

2x ST-DTA12-15WC(4000K) 90PAr @ 12"

so roughly 180PAr @ 12" for 4...


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## jeffkrol (Jun 5, 2013)

gus6464 said:


> You kidding right? You take a naked T5 tube and measure PAR. Now take the same tube and pop it in a reflector, PAR goes way up.


I understand that.. Point is you don't get more than theoretical. and there are ALWAYS losses..
There is no way in [email protected] that a 2700L tube will have the same PAR as a 3500L LED "tube" regardless of reflector.. well unless it concentrates it in under 120 degrees..and at that differential probably not even then. "possibly "equal..

YES you can increase PAR Like theoretical- 10% vs theoretical - 50% (bare tube ) 
If I put 60 degree lenses on that 3500L LED it wil now "increase" PAr at that spot and area but it will not have more than 3500L is capable of..

Photons are photons. You can direct them but you can't change the emitting number..


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## gus6464 (Dec 19, 2011)

jeffkrol said:


> I understand that.. Point is you don't get more than theoretical. and there are ALWAYS losses..
> There is no way in [email protected] that a 2700L tube will have the same PAR as a 3500L LED "tube" regardless of reflector.. well unless it concentrates it in under 120 degrees..and at that differential probably not even then. "possibly "equal..
> 
> YES you can increase PAR Like theoretical- 10% vs theoretical - 50% (bare tube )
> If I put 60 degree lenses on that 3500L LED it wil now "increase" PAr at that spot and area but it will not have more than 3500L is capable of..


A 800L increase is chump change. A reflector in parabolic config made of alanod miro silver 98% will more than double the PAR of a T5 bulb.

Why are you putting LED lenses into the equation? We are talking about LED fluorescent replacement tubes here so that is a moot point. At the end of the day there is not a single LED tube out there that can match the output of the equivalent fluorescent bulb when a reflector is taken into account.

https://www.advancedaquarist.com/2012/5/equipment

Even a crappy reflector doubled the PAR. A better one tripled the PAR. That LED tube that puts out 3500 lumens is no match for a regular 2700 lumen tube with a decent reflector.


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## jeffkrol (Jun 5, 2013)

gus6464 said:


> . At the end of the day there is not a single LED tube out there that can match the output of the equivalent fluorescent bulb when a reflector is taken into account.


There is zero proof of that..as an absolute..you can take crummy 1st gen tubes and use State of the art t8 reflectors and prove your point. but no longer..



> Dual T8 bulbs give a total of only 30 to 40 PAR at 24" depth.
> Yup, the 30 to 40 PAR range is dependent on reflector quality. 40 PAR if top quality reflectors.


let's interpolate my above data a bit:



> 2x ST-DTA12-15WC(4000K) 90PAr @ 12"


assuming 1/2 the PAR of 12" (inverse sq rule doesn't really apply, crunch any chart.) .. they are equal..
lets go to t8. What is the PAr at 12"?
52?.. BTW: Don't consider Hoppy's "accurate" but in the ball park)
Only 10% different.. well w/in margin of error.










2 tubes/diamond plate reflectors..84par @ 12 10% less than LED..

you know the real nice thing:
no worries about how dirty or efficient your reflector is.......... 

http://www.sunritek.com/e/north_america/index.html


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## gus6464 (Dec 19, 2011)

jeffkrol said:


> There is zero proof of that..as an absolute..you can take crummy 1st gen tubes and use State of the art t8 reflectors and prove your point. but no longer..
> 
> 
> let's interpolate my above data a bit:
> ...


A basic 4ft Philips T8 tube puts out 3100-3350 lumens without a reflector. Add a reflector and you now got double the output at least going into the tank. Your fancy 4ft T8 LED tube is putting out 3500 lumens and no reflector is going to help it.


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## jeffkrol (Jun 5, 2013)

Show me PAr numbers.. 
Besides,


> 4ft Philips T8 tube puts out 3100-3350 lumens without a reflector. Add a reflector and you now got double the output


no , you have 3100-3350 Lumens of PAR regardless. Now where you direct them doesn't increase amount..only changes where it goes.
(NOTE: Lumens is a sub-set of PAR)

3350 Lumens of LED contains the exact same PAR as 3350 Lumens of t8 (assuming little out of the range of 400-700nm).
HOW you direct them and percent direction determines the actual #..

Like I said.. I gave you a PAR measurement of a LED tube (*90 @ 12"*) Show me your actual PAR measurements of one tube t8.. w/ any refector you choose at 12"
THEN we can discuss..
I gave you some proving rough equivalence..your turn for real numbers not wishful thinking..



> Here’s The Catch…..What Is The True Output And Where Does That Light Go?
> 
> The fluorescent lamp is an omni-directional light source, shooting light in every direction, and only 1/3 of that light directly lights it’s intended surface. If the tube is mounted in a troffer and even larger portion is reflected within the fixture and really never leaves it.
> 
> LED is a directional light source. It’s lumen output is measured outside the fixture or once the light actually exits the fixture. It’s usable light that is directed towards it’s intended surface vs. scattered and lost from the fluorescent source.


http://www.hoveyelectric.com/hovey-...-Actual-Lumen-Output-For-T8-Fluorescent-Bulbs

let's throw a t5 in here. 118PAR @ 12"


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