Scuba diving light levels

[Cory]

Just curious for those that have been scuba diving, what's it look like down there? How bright is it? I'm talking 30 feet and more.

I've been scuba in Playa del carmen and I was tired from the night before so I didn't go down all the way and my mask kept filling with water. But looking down from the rope i was holding it was black and looking up was bluish but not intense. I could see the sun but the light was dispersed. It wasnt very point source.

I've been thinking that perhaps metal halide and some leds mimick the intensity of shallow reefs that are 6-15 feet deep. And perhaps that's why so many have success with t5s because its blended and less intense mimicking 30 feet deep light levels and
more. And I assume most of our coral come from deeper water. What do you guys think?

 

[Chuk]

Depends on where you are diving, I went in Hawaii down 100 feet and it looked like I was at the bottom of a 8 ft pool. It was bright clear and the corals and fish were very colorful. In Costa Rica it was so murky down 20 feet it was hard to see anything. Everything looked brown and was all silty from the surge.
Typically the first color to go away was red and then it continues on until all that's left is blue. The lighting is very diffused and evenly spread. The only shadowing is produced from the reef itself.

 

[Cory]

Depends on where you are diving, I went in Hawaii down 100 feet and it looked like I was at the bottom of a 8 ft pool. It was bright clear and the corals and fish were very colorful. In Costa Rica it was so murky down 20 feet it was hard to see anything. Everything looked brown and was all silty from the surge.
Typically the first color to go away was red and then it continues on until all that's left is blue. The lighting is very diffused and evenly spread. The only shadowing is produced from the reef itself.

See that's interesting how the lights very diffused. Yeah reds the first to go. I read a post where a guy grew corals on leds that turned out to have better colors than t5s. Nobody believed he could do it. He used radions. 100% blues and 10% whites. Interesting. Deep water colors would be blue and minimal red/green. Maybe most of us are pumping too much reds whites.

 

[Chuk]

I would guess it has to do with how deep his tank is. My understanding is that red from natural sunlight is all absorbed within in the first ~12 inches so having red in your spectrum in a deep tank (such as a public aquarium display) is not going to do much. In a shallower home aquarium it could help bring or highlight out colors that are harder to pick up in the wild.