20K bulbs

[Wee-Reef Master]

OK, I've resisted the switch to 20K (been using Hamilton 14K), but it seems that I'm one of the few that hasn't gone more blue (either with 20K or actinic supplementation). Soooo, I'm entertaining the notion, but I think that XM is waaay too blue for my eye. I saw an Osram 20K in use at a shop that looked like a good mix. Anyone familiar with this bulb? I can't even find it anywhere. Nothing on Sanjay's site. Anyone use any other good 20K bulbs that aren't so blue? I think Tim uses XM 20K. Hard to argue with his success and color.

 

[Unarce]

I've used the XM 20K, Giesemann Megachrome Blue, Phoenix 14K, and Radium. All on HQI ballasts. Of these 4, I liked the Giesemann and Radium best because they weren't too blue.

 

[Justin74]

The ballast your using will play a major role in how blue something is. What kind are you using, and wattage?

-Justin

 

[yoshiod9]

i agree with justin on the ballast call-- i use 20k hamilton bulbs on coralvue ballasts (not sure if they're produced anymore-- and yeah, they're really 20k bulbs!) and love the color.

maybe this will help (although the author never states the ballast he used for the pictures-- or maybe he did and i just overlooked it).
http://www.cnidarianreef.com/lamps.cfm

 

[Unarce]

I don't even want to get into the ballast thing. That's a whole other can of worms. If you're doing single-end, just stick with a good old mag ballast, as you'll really limit yourself in correctly matching bulbs with an HQI ballast.

 

[fishsoldseprtly]

if you go with XM bulbs, the ARO ballasts work perfect with them

 

[Justin74]

The reason why I asked is that a magnetic ballast will slightly overdrive a lamp making it appear a brighter white if using a 20k, with an electronic ballast it will run the bulb to the bulbs specs in turn giving it a more bluer appearance. Dont think that's set in stone, but it's what a few have noticed as well as my self.Ive seen some 14k on e-ballasts that look just like my 20k on it's magnetic ballast. Different bulbs though and wasnt a controlled experiment

-Justin

 

[Wee-Reef Master]

I'm running Ham. 14K on a Ham. electronic ballast and it's nowhere near the blue of most 20K's I've seen. I know that mag. drives the lamp a little harder, thus brighter but I'm unaware of color differences. yoshiod9: Cool link.....thanks! I'm going to study it, along with Sanjy's charts a bit more before I make a move.

 

[Unarce]

Most bulbs available to us here are built for use with a low current ballast, like a mag or electronic. So, you've got quite a few options to choose from.

You'll want to stay away from a few, like Ushio, AB, and AquaConnect, as these are built for high current (i.e. HQI) ballasts. When underdriven, the gases actually become stagnant, reducing the life and usefulness of the bulb. Sort of like overdriving a Radium (low-current bulb) with an HQI ballast. You're doing the opposite, but getting the same result, which is having to switch out the bulb every 4-6 months.

 

[TropTrea]

Well this is something I find had to understand. The big reason we go with Metal Hides is to get a high enough PAR value for our corals to survive. Yet so many people are going to 20K bulbs when it takes at least twice the wattage of 20K to get the PAR as you can get with 6K to 10K bulbs.

Wouldn't it be cheaper going with the XM 10K's then add as much O3 lighting as you want to bring up your blues and get the coral to floresce?

Dennis

 

[Justin74]

<a href=showthread.php?s=&postid=8420551#post8420551 target=_blank>Originally posted</a> by TropTrea
Well this is something I find had to understand. The big reason we go with Metal Hides is to get a high enough PAR value for our corals to survive. Yet so many people are going to 20K bulbs when it takes at least twice the wattage of 20K to get the PAR as you can get with 6K to 10K bulbs.

Wouldn't it be cheaper going with the XM 10K's then add as much O3 lighting as you want to bring up your blues and get the coral to floresce?

Dennis

No, because unless your going to a lower wattage bulb like 175 or 150 your still sucking up the same amount of watts/cost, your just providing higher PAR readings to your tank by using a lower Kelvin bulb.

PAR is not the measurement of usefull light going to a coral, its just a measure of intensity. The debate lies in the spectrum your giving it more so, we just strive for higher PAR readings so we know were giving a sufficient amount of intensity regardless of what spectrum were using. Since we havent pinpointed on what exactly the best spectrum of light to provide are stuff with the debate soon switches to,"well, what color pleases your eye best?" In a kinda round-about sorta way

-Justin