Different Intensities for Lights Across a Tank

[kartrsu]

Went through the latest BRS investigates on lighting and it motivated me to do tweaks to my current setup. Originally I was running 2 Red Sea ReefLED 90s over the Reefer 250 tank, but I noticed shadowing for some acros, especially those under the pucks. I had a spare ReefLED 90, so I added it to the middle of the two lights with the purpose of improving spread and reduce shadowing.

The original lights (left and right pucks) were running at 100%, while the middle had ramped to 20%. I checked with a Apogee PAR meter and was getting good readings across the tank, including the back corners. To provide better spread, I decided to sync all the lights and find the right intensity to match the existing PAR for my acros, when ended up running all 3 lights at 65%. I then checked the PAR in the far corners of the tank and they are like 20-25% lower. Now I'm wondering if this is the right choice. I'm wondering what the community would recommend. I'm confident this new approach will help with spread and reduce hotspots as the acros grow upwards, but I'm also not sure if perhaps running the outer lights higher and the middle light lower is the better approach since the acros are in the middle and the edges are getting less PAR than before.

Tank picture below with the original 100 intensity on edge lights and 20% in the middle.

 

[tzabor10]

Tank is looking amazing. I usually look at tanks I like online and try to copy their setup. @WWC has some excellent videos on home tanks. Personally I like to add light bars to enhance spread. Reefbrite is my favorite but many like Orphek too. There are kits to hang them easily.

 

[kartrsu]

Tank is looking amazing. I usually look at tanks I like online and try to copy their setup. @WWC has some excellent videos on home tanks. Personally I like to add light bars to enhance spread. Reefbrite is my favorite but many like Orphek too. There are kits to hang them easily.

Thanks! I thought about light bars too, but unfortunately non have mounts compatible with red sea lights that are on mounting arms. Could be a DIY project but had a spare red sea light so tried that first.

Man in retrospect, would have been happy to have gotten 2 XR15s instead.

 

[Hooz]

Ok, so, a few thoughts...

1. Push the spacing of the outside lights out towards the edges more. When running multiple lights, there is a lot of overlap. Spacing them evenly doesn't work quite how you'd think.

On a 36" tank, center the outside lights 8" in from each end. That'll light the corners/edges better, and you have the 3rd light in the middle to take up the slack.

2. You were absolutely right before. Because of all the overlap in the middle, the center light will run at a much lower intensity to get a nice EVEN blanket of light.