[Freddy Twotimes]

I am in the process of building a Soft coral reef tank. I have cycled already and am at the point of adding snails. I bought a feather duster and a combo rock with green mushrooms and zoos on it as testers prior to adding any more to the tank. [a 55 gallon]

What I have noticed is that my 196 watt [10000K and actinic bulbs] are not keeping the mushrooms and zoos as green as they were in the LFS. They were using a MH. My corals are doing fine, the water quality is perfect, I do not want hard corals etc. This is a softy tank, but what I do want is very colorful mushrooms and polyps and I want them to spread as time goes on not just keep them alive on whatever rock I purchased them on.

I would like to use a 36" retrofit with a 150 watt MH and two actinics with moon LED's. Will this achieve my goal as described above?

[kevinpo]

Yes it will depending on the distance the corals are from the bulb. Even the PC's will give very good color if the corals are about 12" from the bulb, good water clarity, and no glass tops. The MH just gives a further reach down into the tank. A 150W is good down to about 18-20" for soft corals.

Note: Coloration is not usually an indicator of coral health. A brown or darkened color is usually the corals response to lower lighting and increased zooxanthellae.

HTH,
Kevin

[Freddy Twotimes]

I spoke with my LFS and what I have decided to do was what they have running on a few of thier soft coral tanks. They have a PFO pendant with a single 250 watt 20,000k bulb. It is mounted about 13" above the tank. It has a pretty blue color, it is high enough above the water that the mushrooms and polyps that are located twoard the bottom are doing well. I only have to replace one bulb every 9 months for about the same price as two of the PC bulbs too. It sounds like a worthy improvement for the initial cost of the hardware.

[Reefland]

If your 55 gallon tank has the standard dimensions, 1 metal halide bulb isn't going to provide light to the entire tank. As a general rule, plan for 1 MH per 2'x2' square.

[Freddy Twotimes]

The LFS has tanks that are 44" wide, it seems to be doing fine as far as spreading light across the tank mounted 13" above the water with thier soft corals. How is this possible? [The tank is lit all the way accross]

Will this not work the same way for me?

[kevinpo]

For soft corals it will work fine at the bulb height you are talking about. If you were to lower the light to the normal (for SPS type corals) 6-9" then the light spread in the proper intensity would be aprox. 24"x24" depending on the reflector. As you raise the light the area it covers increases while the intensity decreases. Due to the inverse square law if you raise the light from 6" to 12" the light intensity is reduced to 25% rather than 50%. The opposite occurs if the light is lowered.

HTH,
Kevin
Note: Keep an eye on the plastic center brace if the halide is over it. It can crack over time (1.5 - 2 years or so).

[Freddy Twotimes]

I just purchased a Coralife 48" Advanced strip light. I think it ships with the two 20,000K metal halides. That should allow me to do about anything I want.

After the investment into the light, the bulbs will actually last longer before needing to be replaced so it is actually about the same as swapping out my florescents twice a year.

[vtec si]

Did you look into T5s. They would be more than enough for your tank and cost you a lot less to run than MH and are more intense than PCs.