Struggling to get enough PAR

[pandaparties]

So i have two 48 inch t5/hybrid fixtures for a total of 8 58W t5's and 4 reefi duo extremes on a 108 inch 24 inch tall tank. In my LPS areas i'm doing great on par, hitting about 120-160 running my LED's at around 50% but my section that i have acro's i'm struggling to get my par where i want it. I have my lights around 10 inches off the water and my acros are like 12-16 inches below the surface but even at 100% im getting barely 200 directly under the LED's. I had heard great things about the duo extremes but surprised i'm not getting more. Is it the depth and no matter what light it's going to be a challenge getting 3/400? or are these LED's just underpowered. I don't think even if i add another led next to it i will get much more directly under due to the positioning/length of the LED itself

 

[Timfish]

Light intensity can be cumulative, ie, overlap between two fixtures can be brighter than either fixture by itself. I'd suggest using your PAR meter and do some light field maps with one turned off and with both turned on. That should give you some idea of how much brighter you can make it with a third fixture.

 

[pandaparties]

Light intensity can be cumulative, ie, overlap between two fixtures can be brighter than either fixture by itself. I'd suggest using your PAR meter and do some light field maps with one turned off and with both turned on. That should give you some idea of how much brighter you can make it with a third fixture.

It's more that the lights themselves don't seem to get much more spread than their length if that makes sense? The lights are pretty long like at least 16 inches I think, and the spread is like 24, then even if I place another one right next to it then the middle and far end of the first one get very little overlap from a light perspective. Hopefully I'm explaining that okay. I'll try a third one in one of the fixtures and map it out tomorrow. Just interested to see how other lights compare par wise directly under with a similar depth

 

[oreo54]

So i have two 48 inch t5/hybrid fixtures for a total of 8 58W t5's and 4 reefi duo extremes on a 108 inch 24 inch tall tank. In my LPS areas i'm doing great on par, hitting about 120-160 running my LED's at around 50% but my section that i have acro's i'm struggling to get my par where i want it. I have my lights around 10 inches off the water and my acros are like 12-16 inches below the surface but even at 100% im getting barely 200 directly under the LED's. I had heard great things about the duo extremes but surprised i'm not getting more. Is it the depth and no matter what light it's going to be a challenge getting 3/400? or are these LED's just underpowered. I don't think even if i add another led next to it i will get much more directly under due to the positioning/length of the LED itself

Something doesn't sound right.. What are you using to measure par?
https://www.reefi-lab.com/reefi-led-duo-info/
Now, according to the manuf.. you are really "out of spec"...
your depth of 12-16 and 10" height isn't an issue really.

https://www.reef2reef.com/threads/reefi-led-uno-testing-soon.766239/page-2

Oddly an Uno is quite close to the watt output of a duo.

 

[pandaparties]

I'll post exact readings tomorrow and measurements then and create an actual map, maybe I am doing something wrong... But i am using apogee sq-520 with apogee connect to measure it which supposed to be top of the line.

 

[oreo54]

I'll post exact readings tomorrow and measurements then and create an actual map, maybe I am doing something wrong... But i am using apogee sq-520 with apogee connect to measure it which supposed to be top of the line.

Make sure you checked the "immersion settings" box in the software... or your readings will be off.
you can check for accuracy using the clear sky calculator ect..
I know you probably did but starting w/ simple first.
https://www.manualslib.com/manual/1399676/Apogee-Sq-520.html?page=25#manual

 

[outhouse]

or are these LED's just underpowered

Does not seem like it, they have plenty of watts. My advise is grow coral and quit playing par games, many home readers are crap and not accurate,

par grows nothing your lights do and yours can grow anything