Lighting help...need advice

[stroid]

oh the reason for the 250w is it will work on another setup if need be. I do realize I will need to make sure it is well cooled.

 

[jgoal55]

mufret...as for the Nova fixture....what you say might be true about the light getting to the bottom of the tank but obviously depth has to considered....

I can say that in my tank the light shines about 1 1/2-2 inches into the sand....its very, very bright but it is a shallow thank (30 long). For deeper tanks it may not be adequate.....not sure.

 

[stroid]

Jgoal55;30560 wrote: mufret...as for the Nova fixture....what you say might be true about the light getting to the bottom of the tank but obviously depth has to considered....

I can say that in my tank the light shines about 1 1/2-2 inches into the sand....its very, very bright but it is a shallow thank (30 long). For deeper tanks it may not be adequate.....not sure.

how do you determine how deep the light penetrates into the sand?

 

[jgoal55]

well, i think its light....there is a clear cut line where the sand gets darker against the front glass....its a 3in sand bed......

the bottom inch of the bed against the glass is darker than the first 2 inches....


hopefully that made sense because I am not sure it did.

 

[matttvi]

Stroid;30565 wrote: how do you determine how deep the light penetrates into the sand?

the only way to really know for sure is to use a light meter, and the reef club happens to have one that you can rent...

keep in mind that penetration is not just dependant on the type of lighting, but also:

1. how far the bulbs are hung from the water's surface
2. salt creep on bulbs or uv shield
3. water discoloration - old water turns yellow, light has more difficulty penetrating...

i'm sure there are other reasons as well, but those are the ones I thought of off the top of my head...

hth,

Matt

edit: okay... I should read more carefully... I didn't answer your question. I'm not sure about penetration of the sand bed or why it matters...

 

[stroid]

Matt that explanation helps and I did hear of some light meter that the club has but never really thought to try to rent it. Maybe after i get the light setup i will do that.

 

[jgoal55]

I just assumed that if the light was going into the sand bed then it was penetrating through the water pretty good....

 

[matttvi]

Jgoal55;30586 wrote: I just assumed that if the light was going into the sand bed then it was penetrating through the water pretty good....

illumination and useable light at depth don't always match up. A single 4' standard output Flourescent bulb w/out a reflector will put light on the sand bed of 30" deep tank, but at that depth it's not doing much good...

 

[jgoal55]

gotcha....so then this light meter actually tells you if what you have at the bottom of the tank is usable light?