T5 reflectors question

[Stephers]

I know this is a bit of an odd question. But i'm modifying an existing t5 fixture in order to add LEDs to it and thought I might change out the reflectors to ATI. The only problem is the ATI reflectors are significantly less wide than the ones in there now. So if I were to add them in, because of where the bulb sockets already are placed, the reflectors would not slightly overlap on the ends. There would be about 3/4" between where one reflector ends and the next begins. Will this adversely affect PAR levels at all? Do they just squish them next to each other to save room? Thanks

 

[oreo54]

I know this is a bit of an odd question. But i'm modifying an existing t5 fixture in order to add LEDs to it and thought I might change out the reflectors to ATI. The only problem is the ATI reflectors are significantly less wide than the ones in there now. So if I were to add them in, because of where the bulb sockets already are placed, the reflectors would not slightly overlap on the ends. There would be about 3/4" between where one reflector ends and the next begins. Will this adversely affect PAR levels at all? Do they just squish them next to each other to save room? Thanks

Why? Most leds are lensed at least at 120 degrees meaning their " light cone" is about 3.5" diameter 1" from the diode.

There were a few led aquarium lights with reflectors but they were very small and narrow.

 

[Stephers]

Why? Most leds are lensed at least at 120 degrees meaning their " light cone" is about 3.5" diameter 1" from the diode.

There were a few led aquarium lights with reflectors but they were very small and narrow.

Sorry, to clarify, I'm wanting to change the t5 reflectors to ati since theyre better than the ones currently in the fixture. Im not touching the LEDs.

 

[oreo54]

Ahhhh..

 

[nereefpat]

I think the different size of reflector is a philosophy difference between the older stuff and ATI. The older sunlight company Tek fixtures have a wider spread compared to new ATIs, but the fixture itself is bigger and they didn't have fans to cool the bulbs. The ATIs are a narrower fixture, so you can squeeze an 8 bulb fixture over an 18" wide tank, for example.

I don't know for sure if the PAR will be changed. I guess, theoretically, each bulb would have less spread but more downward. Hard to say. Do you have to change the reflectors to make the LEDs work, or are you just thinking that newer ATI ones are 'better?'

 

[Stephers]

I think the different size of reflector is a philosophy difference between the older stuff and ATI. The older sunlight company Tek fixtures have a wider spread compared to new ATIs, but the fixture itself is bigger and they didn't have fans to cool the bulbs. The ATIs are a narrower fixture, so you can squeeze an 8 bulb fixture over an 18" wide tank, for example.

I don't know for sure if the PAR will be changed. I guess, theoretically, each bulb would have less spread but more downward. Hard to say. Do you have to change the reflectors to make the LEDs work, or are you just thinking that newer ATI ones are 'better?'

Thanks. I definitely don't have to change them, but I already have the ati reflectors and they're rated at 98% reflectivity versus 95% with the preinstalled ones.

Edit: the fixture itself is 18" wide and going over a 75g, so the tank will be completely covered... plan is to have 2 t5 bulbs, 2 kessils, 2 t5 bulbs.

 

[oreo54]

It's not worth chasing 3%...eg 400 vs 388 PAR, 150 vs 145.5
Now narrower angle reflectors may..
I took a back of a napkin wack at it once..

ATI Sunpower Reflector Beam Angle

Does anyone know the beam angle of an individual ATI Sunpower reflector, as in at what angle does the light leave, what's the spread? I know the reflectors in the Powermodule are different and more focused.

www.reef2reef.com

 

[Mywifeisgunnakillme]

From what i remember from many years ago when this debate was at its height the difference in reflectors is much more than 3%... Search some old reef central threads. But switching to ATI versus an unknown reflector i think would be worth a piece of mind.