T5's: A cautionary note

[davejnz]

BLah,Blah,Blah,Blah.Until you can answer my original question,I wont even comment on the MH-vs-T5 penetration topic which you are clearly WRONG about.So,back to my ?,what voltage and at what mA does IC and your beloved WH5 fire T5HO's at?Perhaps if you 2 weren't so busy patting yourselves on the back you would of took the time to research this a little more.So,according to your friend who works on T5's for GE,this is where your getting your info from,correct?.Does he speak Hungarian,LOL.GE's T5HO tubes are manufactured out of the country.O wait,maybe he works here in the US in a factory packaging them,LOL.You claim that higher voltage through the tubes is what causes these phosphors to degrade thus causing spectrum shift.I would post a link for you so you could educate yourself on what T5 bulb manufacturers have to say about this but that would be too easy.
T5HO-----mA-----V------W--------LM--------LM/W
39w-----260----122---31.8-----3000-------94
----------340----115---39-------3500-------90
----------425----109---45.8-----3960-------86
54w-----370----139---50.9-----4790-------93
----------460----135---54-------5000-------91
---------650----121---77.9-----6510-------82
Interesting on how the voltage goes down when the lamps are being overdrived,huh?Guess your high voltage theory needs some more work.Dwdenny,I'll help you take those feet out of your mouth and stick them up this guys ***
Oh,and please stop posting information about phosphors degrading or spectrum shifting unless you have some data to back it up.Clearly your talking where dwdenny just stuck his foot in because otherwise,you would of posted some facts instead of what your Hungarian friend has been telling you.

 

[davejnz]

BTW,If you want to get Grim in on this,we can take this discussion to an alternate forum where i just know he'd be willing to tell you how WRONG you are.
Something tells me you wont take me up on this offer though,drop me or dwdenny a PM and we can arrange it.

 

[dwdenny]

yeah that will work let me know we can do something. he information you are giving out Hahn is wrong and newbies are more then likely going to take it and run.

 

[horkn]

Davejnz just because the ge bulbs are made in hungaria, or other remote eastern european country, does not mean that there are not any lighting engineers here.


if you read up on GE, you would know they have at least 3 (menomonee falls wi, pewaukee, wi, and milwaukee wi) locations here in SE wisconsin. And yes, lighting is one of the departments at at least the pewaukee location. I know this because my GF used to work for GE at that location (different dept) before she took a job at Rockwell Automation.


they may speak a bit of english, as well as hindi or hindu or whatever it is, and maybe, the guys that make and package the bulbs bulbs speak hungarian.

 

[dwdenny]

<a href=showthread.php?s=&postid=7185884#post7185884 target=_blank>Originally posted</a> by hahnmeister
Ok, didnt find what I was looking for, but got it from another source. If anyone can find the exact tests (I believe it was Grim who did them) where he compared % of light intensity lost over 24" of depth (the T5 carried light 2x better).

With halides, or a point source light, the inverse square rule applies, so that if you double the distance from the bulb you decrease the intensity of light by a factor of four. If you are less than one tube length away from the middle of a fluorescent tube, light drops off at an approximately linear rate. That is, if you are two feet away from a 4-foot tube, you receive half (not one quarter) the light that you would receive if you are just one foot away. And if you are in front of the middle of a whole bank of six or more fluorescent tubes, the light intensity at two feet away is almost the same as it is only one foot away! Think about it for a while and you will realize that as you move away from the center of the reflector, you receive more light from the sides, and this compensates for the increasing distance. This works as long as you are still closer to the center of the reflector than the reflector is wide. So a multiple tube fluorescent light fixture produces a very even light throughout the depth of a tank. If you want to defeat the inverse square law, get more tubes.

I hope you washed those feet before you stuck them in your mouth dwdenny. lol...

It's all about what you can get though the surface of the water. A photon is a photon wether it was create by a halide or a candle. Once they hit the water they are all going to travel the same distance. Halides start out much more intense so they have an advantage. The disadvantage is they have to be place farther away from the water. The Inverse Square Law explains why the halides can be beat by much less intense fluorescents. A halide mounted 8" above the tank has to be twice as intense as the t5 array mounted 4" above the tank (assuming both are using parabolic reflectors) to be equal intensity once they hit the water.

 

[Obi-dad]

dwdenny - well said. The arguments about MH 'being the best' or 'having more punch' are silly and are some of the most often repeated ill-informed statements here on RC. 'A photon is a photon wether it was created by a halide or a candle.' Absolutely true (for any given wavelength).

Whether you have light deep in the tank on the sandbed is determined by the setup - a poorly designed MH reflector will not give high light on the sandbed, as would not using the proper reflectors for T5. Add in the height of bulbs above the water and the number of bulbs as other factors in the setup.

A PAR meter will tell the truth about a given setup, whether MH or T5. I have used the club's PAR meter and it is easy to show that T5s can have high light levels on the sandbed, and also showed that a poor MH reflector with low PAR MH bulb had low light on the sandbed. It is time to give the fictions of 'MH is the best' and 'MH have more punch' a rest.

 

[hahnmeister]

"The Inverse Square Law explains why the halides can be beat by much less intense fluorescents." -dwdenny

Thank you, that was my whole point that you claim I am wrong about, yet you just repeated it in your last post. So what was I 'wrong' about? Halides are more intense at shorter distances, no doubt about it, due to their sheer output/wattage, but the original challenge was for me to prove that T5s penetrate deeper than halides, and they do, up to a distance from the bulb equal to the bulb's length. You have to compare apples to apples here though. If you have 400watts halide vs. 216 watts T5, well, yeah, the halide is just more intense to begin with. If I were to compare PAR readings from 216 watts of T5 vs. 250watts of hlaide however...the T5 would smoke the halide from about 18" of depth and on deeper. I should know, I have a meter and both lighting setups. The halide is great for intensity near the bulb, but taller tanks naturally lend themselves to T5.

 

[hahnmeister]

davejnz, I dont know where you are coming from. You state I am clearly wrong about something, but have yet to clarify what about. I have proven that linear output bulbs carry their intensity deeper into our tanks than halides, both dwdenny and Obi-dad agree with that.

As for the GE contact. You dont have to believe me and its hardly relevant. I know, and if you look through GE's website, you will see many lighting engineer positions available where I live. They might be made in Hungary, and packaged elsewhere, but the R&D is here.

As for the voltage numbers that you are posting, they mean very little. The voltage might be going down, but thats because the amps is going up...so the wattage stays the same. In the past, the most common way to boost a flo bulb was through boosting the voltage, because manipulating the amps wasnt an option.

To narrow down that whole argument, I would challenge anyone to use a laser thermometer to measure the temps of both a normally driven T5 bulb compared to an overdriven (IC660) T5 bulb. This is what it comes down to.

as far as "Oh,and please stop posting information about phosphors degrading or spectrum shifting unless you have some data to back it up". I dont have to. phosphors degrade due to heat. Thats too basic to have to back up.

Back to the beginning, someone said that I was 'full of it' for stating that T5s penetrate 2x as much as T5s. That is a fact of any linear bulb up to the length of the bulb (so if you are running 4' T5s on a tank that is over 48" tall, let me know).

Where am I WRONG here?

 

[horkn]

i have said laser thermometer. its called a digital pyrometer. many times it is used for measuring temps of tires in race cars and such. I use mine for measuring temps of tires when I am at the racetrack on my bike.

I ahve used mine for measuring other temps too, like how hot each pump gets for lacal heating in my tank, as well as temp of lights,a nd ballasts. its really pretty useful.

since i have a second. let me post up the reults of my digital pyrometer on my t5ho retro, since it now has been on a few hours.

 

[hahnmeister]

Thanks horkn. That will help. But do you have a way of posting temps from equal wattage bulbs running on IC and spec T5 ballasts? We need a comparison here...

 

[horkn]

i dont have an icecap, so i cant comment on that, but maybe someone else close to me does have an IC overdriven t5ho setup.

however. i just measured between 92-94 degrees on my workhorse 5 ballast. thta seems totally in line with what i figured. and for another example, my digital pyrometer measured 160 degrees on middle of the (ati blue) t5ho bulb.

suprisingly, the GE 6500k bulb is running at 104 Degrees.
wierd huh? maybe its the blue spectrum holding more heat in that the whitish color of the ge bulb?
i see that some say that t5ho is supposed to run at 90 degrees. If that is the case, then my setup does run hotter. but if the wballast make less par than advance or triad or other ballasts, then i couldnt imagine the other ballasts making then t5 bulbs run cooler. I esp doubt that an icecap 430 or 660 will run the bulbs cooler. btw, i have no fans in my canopy, and its half open in back.

 

[horkn]

i dont have a spec t5ho ballast either. maybe i can get a reading from JD's yours or someone elses t5ho setup? the problem is the tek light has the ballasts encased, and i doubt JD will want to take his apart just to get a temp reading on the ballast.


johns is a WRS member as well, and has his tank lit by t5ho, so, in the next feww weeks we could have results, all from the same pyrometer.

 

[hahnmeister]

All I need is a laser thermometer, and I could take readings off my 6x39wattT5 and I could set up my IC660 with 4x54wattT5s thats sitting around doing nothing...

The biggest thing I notice is just how much brighter the 6x39watt T5 tek is than my 250wattHQI halide. Its impressive to see in person, and not that the 'color' of both tanks is nearly the same as far as how I matched the bulbs, so its not like I have a bluer halide and a whiter T5.

 

[horkn]

and this is the instrument i used to get those numbers.

 

[horkn]

jon, write me at the wrs yahoogroup. i can loan you this pyrometer for about 2 weeks.

-Tom

 

[davejnz]

If its so basic,then why cant you show me one single test comparing a bulbs spectral analysis over the course of an 18 month period.And for the heat thing,DUH,I think its obvious that an overdriven bulb will produce more heat than a normally driven.I've never disagreed with you on this.I will CHALLENGE any of you on this thread to prove your
"theory" by showing me some real data by way of spectral analysis.
BTW,I wonder why computer chip manufacturers design there chips to run at low voltages?less heat perhaps?WH ballasts,last i checked are have a nominal line output voltage of 600vRMS.THat,combined with there high voltage,"instant start" type of firing has got to be pretty hard on those phosphors(since your voltage theory must be right).

 

[hahnmeister]

Ok, davejnz, the only thing I thought we were debating was that T5's penetrated better than halides. As far as any other 'theories' that you would like to challenge, please clarify. Spectral analysis equipment is in the $$thousands$$ and so beyond all of us, but I dont remember spectral analysis ever coming up before in this thread.

But one thing is for sure, the starting mechanism, soft start, instant, etc...it has nothing to do with the phosphors. Heat is all that matters, and every bit of data I have seen so far shows that the IC runs the bulbs hotter than spec...so the bulb life would be decreased (from the website on T5s I posted before, 95 degrees is the ideal).

Im still wondering, what am i so WRONG about? If anything, i was told I was pulling stuff out of my @$$ for saying T5s penetrate 2x as good in our aquariums. I proved it. Why are you continuing to talk about appendages in orifaces?

 

[davejnz]

<a href=showthread.php?s=&postid=7183348#post7183348 target=_blank>Originally posted</a> by hahnmeister
The penetration of T5s is double that of halides, due to the linear output.
Then there is my 60g cube. Its 24" dimensions would mean that I would have to sun something like 8x24wattT5...and at that, I still wouldnt get the intensity I would with a single lumenarc/halide.

Now,who's putting there foot in their mouth.Your 2x penetration theory has just been contradicted by your own post.

 

[horkn]

davejnz, all I am proving is that the w ballasts are not bad at all to run on t5ho setups. 15+ months on the same bulbs driven by a w ballast with no dark bands show me this. I could care less about spectral analysis really. I have seen good coral growth from both t5ho lit tanks, and from Mh lit tanks.

that is why i am doing my new 90 with both mh and t5ho.


no reply on the GE engineering dept in hungary?

 

[davejnz]

<a href=showthread.php?s=&postid=7187871#post7187871 target=_blank>Originally posted</a> by hahnmeister
Ok, davejnz, the only thing I thought we were debating was that T5's penetrated better than halides. As far as any other 'theories' that you would like to challenge, please clarify. Spectral analysis equipment is in the $$thousands$$ and so beyond all of us, but I dont remember spectral analysis ever coming up before in this thread.

Why dont you go back and read my first post then.