MarsAqua hot spots

[gobble]

Someone noticed in a post I made yesterday the light pattern hitting the bottom of my frag tank with two Mars Aqua lights mounted above. I removed the eggcrate to better show the effect. Here it is with all blue and both blue and white. The pattern is very tight with these lights. Note the bottom of the tank has a little sand so that is the dirt you see.

 

[saltyfilmfolks]

That was me!!!

What are the dimensions of the frag tank?

How high above the tank are they?

 

[gobble]

The tank is 48" x 24", 12" above the water.

 

[oreo54]

Raise the light or take the lenses off the blue led's.. Look more like 60 degree than 90's actually but ????..
That's a very shallow tank..

 

[gobble]

Here's a picture of two G3 Radions mounted over the same tank. They currently have the wide angle lenses installed.

 

[rosshamsandwich]

90 degree lens do not have as much hotspots?

 

[lbacha]

I just replaced my 16" sbreef over my frag tank. It's 24x12 and only 7" tall. I tried pulling the lenses and while it spread the par out I had to run it at 100% and it was a little under 200par in the middle and 150 on the edges.

If I left the reflectors on and raised it up I still couldn't get high par on the edges without doubling the par in the middle.

I think in a deeper mixed reef tank where I could place lps or lower light demanding coral in the low light areas the black box would have worked fine but for a small sps dominant frag tank where I wanted to take advantage of the whole tank it didn't do what I wanted

 

[rosshamsandwich]

I pulled the lens only on the middle in a circular pattern to avoid the hot spots..... did you try that?? i think it makes for a more diffuse light withsame par relatively all throughout the tank

 

[rosshamsandwich]

i pulled off six lenses total..

 

[lbacha]

I pulled the lens only on the middle in a circular pattern to avoid the hot spots..... did you try that?? i think it makes for a more diffuse light withsame par relatively all throughout the tank

If pulling the lenses didn't require taking it apart I probably would have played with it a little more. I used it as an excuse to buy a new Orphek Atlantik.

 

[rosshamsandwich]

Orphek Atlantik also uses 90 degree optics... how is it not going to have hotspots as well? the LED configuration is the same?

 

[lbacha]

Orphek Atlantik also uses 90 degree optics... how is it not going to have hotspots as well? the LED configuration is the same?

The bigger size of the fixture allows me to avoid hot spots I'm guessing. The light is also diffused through a 1/4" acrylic sheet which I'm guessing helps. I measured par for it and it was within 20-30 par over my whole 24x12 tank. (I based my purchase off BRS's par readings which showed no hot spots at 6"-24")

I tested at 200par and 300par (I'm starting at 200 and plan on ramping up to 300 over then next month or so)