Metal Halide Question

[sharko88]

Okay here are the facts:

Tank is a custom tank. It dimensions are: 36"L x 18"W x 20"H.

I have a canopy on the tank that measures about 7" tall. I have a sand bed in the tank that is about 3" tall.

Here is the Question:

I am going to make the move to Metal Halides so I can keep some SPS. Will 2 x 150W HQI's mounted 7" high be powerful enough for SPS corals (arcos, birdsnest, etc.) or clams on a 20" high tank with a 3" sandbed if the corals were on the top of the sand (mounted to a flat piece of rock)?

The net height ends up to being 24".

 

[crt81]

Well any closer to the water, might be pushing it! MH fixtures should,'t come incontact with the water, will cause major issues!

 

[sharko88]

I do have a glass top on the aquarium to protect it.

 

[Felix1021]

I say 7-8 inches off the water surface should be enough

Felix-

 

[JENnKerry]

Those lights will be fine for what you want.

 

[seapug]

I'd suggest you remove your glass top to get some air circulation going at the water surface or you could end of with some heat issues from the MH. Plus, it's just better for your tank. If you are worried about jumpers make something out of plexi or glass that has lots of small holes in it to maintain air exchange.

 

[watercolour]

What sort of issues can MH lights being too close cause? Also I have a 175w pendant in which the bulb will hang vertically over the tank as opposed to a horizontally mounted bulb. Is this bad or likely insufficient? Thanks!

 

[bertoni]

[welcome]

The closer they are to the tank, the more light and heat that get put into the water. Either of those might cause a problem.

A vertical bulb probably isn't going to be very efficient, I think, but a lot depends on the exact product.

 

[ahullsb]

And I agree that w 150's will be plenty of light for that tank.