calculating lumen output from the sun...

[maxpower39]

what is the typical amount of lumens produced by the sun in 30 ft of ocean in a four by two by three area?
is there a formula for calculating this?
is there a formula for calculating lumen output of the bulbs we use...???
thanks reefers!!!

 

[maxpower39]

bump^

 

[maxpower39]

bump^

 

[ReeferAl]

There isn't much talk about lumen output by the sun (or reef aquarium lighting) as it is a pretty useless measure when it comes to corals, plants or most other biological systems.

The light intensity of the sun in relation to coral reefs is usually discussed in terms of PAR, measured in PPFD. At noon on the surface of the ocean in the tropics it is about 2000 ppfd and drops to about 600 at 10m and about 200 at 20m.

A quantum meter is used to measure PAR rather than a lux meter. A review of a relatively affordable quantum meter is here:
http://www.advancedaquarist.com/2005/7/review

This is an article showing some representative PAR values in reef tanks:
http://www.advancedaquarist.com/2005/8/lines/view?searchterm=

Allen