how high do you or should you keep MH

[wingman1234]

i have a 90g tank 24 inche how high should i have the MH above the water line.

 

[Kenzy]

Depends...

What wattage MH?

What type of reflector?

What type of corals do you want?

On my 90g I had a single 400w MH with a cheap reflector, the lamp was at 8" above the water.

Would need to know what you have, and want to keep.

 

[wingman1234]

i have a sunpod 250w with a retrofit 4x65 watt pc lights, i am thinking of keeping mostly sps corals

 

[tatkinson]

Like Kenzy, mine is at 8". Depending on how "perfect" you want to get, a lot is going to depend on your aquascape and your reflector. If you have the data on your reflector it will help you decide how high it needs to be to get the coverage you want. There is not one universal answer since every tank is different. My suggestion would be to just run the halide with the PCs off and then dial in the height to get the spread you want. You can really over analyze it but, in my opinion, I'd play with different heights to get the look you want. Once you like the way the lighting in your tank looks you can place your corals where they should be based on their light needs...unless you already have definite opinions as to what corals you want where. Then it's a totally different story.

 

[fufu]

I put mine 8" above the water, Basically how tall my canopy allow me to put it. Works fine and I have almost no salt on the reflector.

 

[Toddrtrex]

There is no set height. Use what will give you the best light spread and keep the temps where you want them. Plus, you might be concerned with light spill over depending on where/how the tank is set up.

For example, the fixture for my 58 sits right on top of the tank itself. It is only a 3 foot long tank, and I have 2*250, so I am not worried about light spread. However, I didn't want any light spill over, since the tank is in my living room. (( or family room, what ever the TV room is called. ))

 

[wingman1234]

thank every one

 

[JAustin]

my single 400w halide is 16" off the water on my 60g reef.

 

[mr&mrsfish]

I have three 250 watt MHs over a six foot long tank. These are positioned 10" above the water line. This works well on a 2' wide X 2' deep tank.

 

[GaryR1984]

My OuterOrbit is 4" above the water line using the standard legs.