250W how high off the tank?

[kysard1]

I am building a canopy. It will house a 250W MH SE 10K Ushio. The tank is 21"- 3" Sand Bed. I wanted to make the canopy 12" tall putting the 250W almost 30" away from the bottom of the tank. Every post I find mentions water distance but I am concerned about total distance.

 

[samherston]

You want the bulbs to be a MIN of 10 inches off the water and really 12 inches off the water is best!

 

[Rovert]

I have my lamps about 5" off the water line, and the depth of my sand bed is about 19" below the water line. That makes the total distance about 24".

I wouldn't get too hung up on distance alone. You have to also factor for the lamps themselves in the equation. For example, if a minimum of 10" is for 250's, does that mean that if you have 400's you have to place them 16" above the water because 400's are 60% brighter than 250's?

IMO, as long as they're not going to be splashed and risk a break, your animals are properly acclimated, and you're satisfied with the look, it's all good. Use your judgment.

 

[kysard1]

Well I wanted to build the canopy 12 inches tall, just wasn't sure if this might be too far away for the clams. thanks

 

[Rovert]

You might try making the canopy in such a way that you can raise or lower it depending on what you like. Why not start mounting lights on a very basic frame, experiment with different heights, and then when you find what you like, put the facings on it.

 

[jnb]

why so far off the water?

<a href=showthread.php?s=&postid=10194691#post10194691 target=_blank>Originally posted</a> by samherston
You want the bulbs to be a MIN of 10 inches off the water and really 12 inches off the water is best!

 

[kysard1]

<a href=showthread.php?s=&postid=10239193#post10239193 target=_blank>Originally posted</a> by jnb
why so far off the water?

- less salt creep
- Easier to reach under/around
- Less heat radiation/better cooling
- Single bulb, so wider coverage.