Metal Halide Height

[kaiser]

I just bought me a 250 WATT DE HQI REEFSTAR DE Pendant w/ 10K ushio. How high should I hang this of the Water surface? also since this is going to be my only light I am going to use. Do I need to get a 20K? Anybody else have experience with this set-up?

[Ram_Puppy]

As to getting a 20K or not, I think what type of animals you have in your tank would decide that.

[GaryP]

Kaiser,

I think 20K is a good bulb for supplementsl lighting in a large tank, but not as a primary light. I use VHO actinic, which is basically 20K, in my tanks as a supplement. Besides, the par value for 20K is pretty low compared to 10K and it might look a little dim.

Gary

[kaiser]

It is going to be over a 37 Cube. All I got right now are softies. I would like a clam in the near future. Maybe even some SPS.

[GaryP]

You might want to consider something like a 12-14K bulb. That's what I'm running in my 125 right now. They call it a "blue" 10K.

Gary

[matt]

Remember that there are "10k" like ushio and "10k" like the blueline bulbs, and they don't look anything alike, and they have radically different intensities. The best source of info I've seen about bulbs is the series of tests that Sanjay Joshi has done. You can find them on either reefkeeping or advanced aquarist on line mags, I think.

The 10k ushio bulb you have is a classic, and for a long time has been considered by many to be the overall most advantageous combination of color and intensity. But, the XM 10k has significantly higher PAR than the ushio, and seems to be a little bluer, which most people find preferable. I've been using the 10k ushios, in fact it's the only mh bulb I've ever had, but soon I'm going to try the 10k XM. On my old 45 breeder I used 175W ushios without any actinic support and I loved it. These were mogule base bulbs. You have the D.E. bulb, which supposedly has a nicer color and more PAR than the mogule bulb at the same wattage. I have a feeling that your bulb will do VERY well for light demanding corals and clams.

One thing to consider is that Tim Marvin said that he coudn't get the XM bulb to fire with an icecap ballast; if yours is the old-style icecap, this could be a consideration.

[kaiser]

I think Tim was trying to fire a DE with a mogul type ballast. The new icecap electronic Ballasts are supposed to fire DE. The Unit I bought has a HQI ballast with it. I may change that out down the line with an electronic ballast.

[matt]

Right, but there's something funny about XM bulbs and electronic ballasts, I know I've heard that somewhere.

[Gator]

i run all electronic blueline baqllasts with 6 xm bulbs and ihave not had a problem fyi

[matt]

Maybe it's just the old style icecaps. At one point, I was considering icecaps and XMs, then heard that XMs don't do well on those ballasts, then recently Josh said something about how they fixed that with the newer icecaps.

[Ram_Puppy]

hmm.. I have a 175 watt 10K xm and I am not impressed, the light is visibly yellow, not much, but it is there, not at all what I expected from a bulb reported to be white with a hint of blue. Maybe it's my ballast... don't know... not to worried as I am planning on switching it all out in the future for 400's.

[RobertG]

I think Tim was trying to fire a DE with a mogul type ballast. The new icecap electronic Ballasts are supposed to fire DE. The Unit I bought has a HQI ballast with it. I may change that out down the line with an electronic ballast.

No Tim was using the IC Electronic Ballast DE , I bought his XM Bulbs from him, never fired on my IC but did fine on my magnetic ballast. He tried numerous ballast before selling me these bulbs. He bought a new IC still no fire. The Xm's have a nice color tone to them more blue than the yellow looking Giessmann's I have.
I was going to try the XM bulb on my Geissmann Electronic ballast, see if they fire on them. Will see...