ReefBreeders Photon Par Questions

[squarereefer]

I’m hoping to get some input from others who have experience dialing in LED lighting, especially Reef Breeders on tanks that are wider than the fixture.

I recently mounted a Photon V2 Pro 24" over my 35" x 24" x 20" tank. The light is centered and mounted at the BRS-recommended 14" height.

I’m currently borrowing a PAR meter and running some tests using the BRS-recommended spectrum (100% blues, 50% whites, 20% red/green), along with a scaled-down version at 60% overall power (60% blues, 30% whites, 12% red/green).

I fully expected some PAR falloff toward the ends of the tank given the fixture length, but I’m seeing a much more significant drop than I anticipated. I’m also noticing a pretty dramatic drop front-to-back, which surprised me.

The part that really has me scratching my head: along the outer edges where PAR is lower near the surface, it actually seems to increase as I go deeper in the water column and doesn't seem to fall off much between 8-16" depth.

Is that kind of pattern normal with this type of LED and mounting height?

For those running a similar setup:

• What kind of spread and PAR distribution are you seeing?
• What mounting height are you running? I don't have a good option to mount higher.
• Any tips for improving edge and front-to-back coverage?

Appreciate any insight—just trying to understand what I’m seeing before I start making adjustments.

PS - I dislike my aqua scape and coral layout but it's a bit late in the game to change it. I am working up the courage to snap the top center rock off and trade the whole thing to my LFS since having Zoas as the focal point and sitting at high par is not ideal. They do seem to be adjusted to high par after living under Noops the last two years but I know the layout is horrible. Ideally I will place a flat rock or bridge a little lower once the middle rock is gone and use that as a mounting place for a couple of SPS Stick corals.

TL&DR - Here my light spread at 60% and 100% Power on a Photon v2 24" over a 35x24x20 tank. Is it ok and how can (or should) I improve?

100%

 

[oreo54]

I’m hoping to get some input from others who have experience dialing in LED lighting, especially Reef Breeders on tanks that are wider than the fixture.

I recently mounted a Photon V2 Pro 24" over my 35" x 24" x 20" tank. The light is centered and mounted at the BRS-recommended 14" height.

I’m currently borrowing a PAR meter and running some tests using the BRS-recommended spectrum (100% blues, 50% whites, 20% red/green), along with a scaled-down version at 60% overall power (60% blues, 30% whites, 12% red/green).

I fully expected some PAR falloff toward the ends of the tank given the fixture length, but I’m seeing a much more significant drop than I anticipated. I’m also noticing a pretty dramatic drop front-to-back, which surprised me.

The part that really has me scratching my head: along the outer edges where PAR is lower near the surface, it actually seems to increase as I go deeper in the water column and doesn't seem to fall off much between 8-16" depth.

Is that kind of pattern normal with this type of LED and mounting height?

For those running a similar setup:

• What kind of spread and PAR distribution are you seeing?
• What mounting height are you running? I don't have a good option to mount higher.
• Any tips for improving edge and front-to-back coverage?

Appreciate any insight—just trying to understand what I’m seeing before I start making adjustments.

PS - I dislike my aqua scape and coral layout but it's a bit late in the game to change it. I am working up the courage to snap the top center rock off and trade the whole thing to my LFS since having Zoas as the focal point and sitting at high par is not ideal. They do seem to be adjusted to high par after living under Noops the last two years but I know the layout is horrible. Ideally I will place a flat rock or bridge a little lower once the middle rock is gone and use that as a mounting place for a couple of SPS Stick corals.

TL&DR - Here my light spread at 60% and 100% Power on a Photon v2 24" over a 35x24x20 tank. Is it ok and how can (or should) I improve?

100%

What par meter are you using?

 

[squarereefer]

What par meter are you using?

I am using a VBR-Aqua borrowed from a LFS. It looks to be an inexpensive Amazon unit but has decent ratings but I do question if it's accurate. I have all flow turned off for the readings.

 

[X-37B]

This is my photon 24 on my 24×20×20.
14" off the surface.
Blue violet 70%
Red green 40%
White 50%
Par 350 higher nem 330 hammer 260 bottom sand. Parwise meter.
Are you sure all leds are working. The pic looks like some are not on.

 

[oreo54]

I am using a VBR-Aqua borrowed from a LFS. It looks to be an inexpensive Amazon unit but has decent ratings but I do question if it's accurate. I have all flow turned off for the readings.

Well I'm a bit more concern on if it was cosine corrected or not.
If not the sensor is very directional.

24" lights on 36" tanks isn't always ideal .
At the expense of some more light spill you may consider raising the light a bit
Say 1-2".

 

[squarereefer]

Good question re: cosine - at the price point, likely not. It did seem very directional with any tilt affecting the reading, so I was as careful as possible to keep it flat and pointing straight up.

I'd love to raise another 2" but the best I can do is 15" with the BOT mount and the readings between 14-15" didn't seem to change on the outer edges. I'll bump it back to 15" for good measure.

@X-37B your tank looks great! as best I can tell, all of my LEDs are own, although the ones with the arrows look a bit different. What do you think @Reef Breeders ?

 

[steveschuerger]

I had a ReefBreeders 32. It’s quite meant for that length tank . I.e: 3 foot class(I had mine over both a Nuvo 30l and SR60 which were 35 inches long).
It needed help when I went to a 4’ 90. In short, the light is too short for full coverage, esp around the edges. I had a ReeFi uno to make up the difference but unless you’re willing to put up with the ends in particular being par starved you might want to look for a new light unless you can augment with bars say.

 

[X-37B]

Good question re: cosine - at the price point, likely not. It did seem very directional with any tilt affecting the reading, so I was as careful as possible to keep it flat and pointing straight up.

I'd love to raise another 2" but the best I can do is 15" with the BOT mount and the readings between 14-15" didn't seem to change on the outer edges. I'll bump it back to 15" for good measure.

@X-37B your tank looks great! as best I can tell, all of my LEDs are own, although the ones with the arrows look a bit different. What do you think @Reef Breeders ?

Those are the uv's so they look dim.
I run two photon 50's on my 150 60×30×21. 50's are 48" and par at the ends is less, like 200ish.
I would try to get another par meter to compare.
Your par is most likely higher than you have recorded.
My 150

 

[squarereefer]

Those are the uv's so they look dim.
I run two photon 50's on my 150 60×30×21. 50's are 48" and par at the ends is less, like 200ish.
I would try to get another par meter to compare.
Your par is most likely higher than you have recorded.
My 150

Beautiful tank! Agreed on meter and will make the drive to rent an apogee from a further away store.

 

[exnisstech]

Those are the uv's so they look dim.
I run two photon 50's on my 150 60×30×21. 50's are 48" and par at the ends is less, like 200ish.
I would try to get another par meter to compare.
Your par is most likely higher than you have recorded.
My 150

Similar here except two 32 pros over a 36x22x22" tank 10" above the water.

Have to zoom in. Sorry for the poor choice of text, I'm working in my tech skills.

 

[Science/G]

This is my photon 24 on my 24×20×20.
14" off the surface.
Blue violet 70%
Red green 40%
White 50%
Par 350 higher nem 330 hammer 260 bottom sand. Parwise meter.
Are you sure all leds are working. The pic looks like some are not on.

Yeah I agree it looks like half of your array is not working

 

[Science/G]

Yeah I agree it looks like half of your array is not working

Okay now I see those are the UVs
Yeah I would think about raising the lights up and increasing the intensity

 

[Reef Breeders]

Good question re: cosine - at the price point, likely not. It did seem very directional with any tilt affecting the reading, so I was as careful as possible to keep it flat and pointing straight up.

I'd love to raise another 2" but the best I can do is 15" with the BOT mount and the readings between 14-15" didn't seem to change on the outer edges. I'll bump it back to 15" for good measure.

@X-37B your tank looks great! as best I can tell, all of my LEDs are own, although the ones with the arrows look a bit different. What do you think @Reef Breeders ?

Those are violet LED’s they are always dimmer by nature. If you need more spread your best option is to raise the Photon up higher and see if that fixes the issue and if you can get an Apogee 510 to cross reference the PAR meter you are using.