What colour light?

[wozza]

Hi im getting a second hand one of these 2marrow
and the guy said the bulbs are old and need replaceing

Giesemann Aquarium Lighting Systems - System 230

I would like to keep mostly LPS and some soft corals.
what kelvin/temp/colour (not sure of the correct termenolgy) lamp would you suggest for them?

thanks james

[Reefland]

I like the Phoenix 14k, some might think they are too blue others might think not blue enough. It is a big personal preference in choosing the bulb.

[Ninong]

That fixture comes with either 70w, 150w or 250w lamps. I assume that the one you are buying has either 150w or 250w lamps.

It comes with Giesemann lamps but you could use any double-ended metal halide lamps of the same wattage. I like the Ushio/BLV 10,000K lamps myself. My second choice would be AB-10000 lamps in either 150w or 250w DE. Giesemann, Ushio/BLV and AB all claim their 10,000K lamps are actually 13,000K. At least that's what they claim. I have used 250w lamps in both BLV and AB and I like them both but I think I like the BLV better. In the U.K., you will probably find them under the BLV brand.

If you prefer something bluer, you could try something with a higher Kelvin rating but you would give up a lot of PAR. If your lamps are only 150w, then you're pretty much stuck with the 10,000K because the 14,000K or 15,000K or 20,000K wouldn't put out enough PAR.

[wozza]

Oh sorry i didnt say what what they are: its the 150w fixture with the 2x9w actanic PC's .
i dont like it to be to blue, and ide go with what ever has the highest PAR anyhow and just suplemt with PC's to achive the colour i like.

thanks you two, i think ill go with the Ushio/BLV 10,000K i found a UK site that sells them so thats cool.

on more thing my tank is 100cm wide x 30cm deep x 40cm tall
How high should i have the light of the surface of the water?

cheers james

[Ninong]

Oh sorry i didnt say what what they are: its the 150w fixture with the 2x9w actanic PC's .

OK, so it's the 2-ft (60cm) fixture with a single 150w metal halide plus two little 9w PC actinics.

thanks you two, i think ill go with the Ushio/BLV 10,000K i found a UK site that sells them so thats cool.

Yes, that would be a good idea.

on more thing my tank is 100cm wide x 30cm deep x 40cm tall
How high should i have the light of the surface of the water?

According to the manufacturer's instructions, you are supposed to position that fixture so that the bottom of the fixture is 30cm (12") above the surface of the water. You could position it a little closer if you like but I don't think I'd put it any closer than 9" (23cm) above the surface.

[wozza]

The cables that the thing came with are not very long and only reach to have the light 16inches off the water surface.

How will this effect it performance??

cheers james

[Ninong]

Sixteen inches is much too high for a 150w metal halide lamp. It will significantly reduce the intensity of the light incident on the corals in the tank.

You need to figure out a way to get the bottom of the fixture no more than 12" above the surface of the water. In my opinion, 10" would be even better.

Good luck!



P.S. -- You can operate the tank with the fixture 16" above the water but it will definitely reduce your options when it comes to what you can keep under that lighting intensity.

[wozza]

yep no worrys thats what i thorght, im gonna go in to town to the local bike shop and get some break cable wire. its the same as the wire it came with!

cheers james