How Many Lumen Do I Need For 7 X 2 X 2

[clivealive]

how many lumen do i need for 7 x 2 x 2
 
i want good strong light for tropical tank.
 
to show fish colour of to best affect.
 
 
???

 

[Byron]

Ironically, less light will usually cause fish to be more colourful.  Most fish are forest fish, living in fairly dimly-lit waters.  They will be more "relaxed" with less overhead light because it is more natural, and thus show better colouration.  Bright light will often cause fish to become somewhat pale.
 
Byron.

 

[StevenF]

I have been using lumens per squar inch:
http/fotohobbist.com/blog/aquarium-lighting-for-planted-aquariums/#more-136
 
So for grigght light you would need  60480 lumens evenly scattered accross the substrate surface.  However I only have a small starter tank at the moment so I don't know hit the recommentdation is accurate for a 7X2X2.
 

 
 
Ironically, less light will usually cause fish to be more colourful.  Most fish are forest fish, living in fairly dimly-lit waters.  They will be more "relaxed" with less overhead light because it is more natural, and thus show better colouration.  Bright light will often cause fish to become somewhat pale.

 
If you put a light meter on the grond with full sun and clear skys it should read about 24,000 lumens.  Even under a forest you will typically havre more light than in the typical room in a home at night.  30 lumens per square inch is a lot less than typical light levels in shade.  outside.  That said using a darker substrate should help the fish feel more comfortable.

 

[brandoncw]

also in contrast to byrons post, too dim makes fish pale. when my tank was dark for just an hour my piranhas belly was nearly white but wiht the lights on it turned blood red. im not syaing Byron is wrong, im saying i think there is a happy medium.

 

[Byron]

We are tossing around subjective terms like "too bright," "dim," etc, and such terms naturally mean very different things to different individuals.  The OP used the phrase "good strong light," and that too may mean something very different, but the bottom line is that "strong light" is not something fish appreciate above them because it is unnatural.  Floating plants can do a lot to alleviate this.