Anyone used the 250W 20K bulbs?

[Reedman]

I was hoping to get some opinions from those that have used these bulbs. I always here about the 400W radiums, but was wondering is anyone has tried the 250W 20K bulbs. Please give your opinions and why you liked or disliked these bulbs.

Thanks.

[Jimbo]

Hi I looked around for information on the radium 20k 250w. On hellolights website, they do not guarente that the bulb will light with a standard 250 watt ballast. Here's a quote from there webpage
[

A. The 250W Radium lamp is a European lamp for European ballast applications. The lamp was designed for a reactor ballast used for 220/240V input voltage and not for 120V operation in the U.S. Most people have success with standard 250W metal halide but it is marginal starting voltage and the lamp sometimes does not start (most of the time it starts fine). We test each lamp using a standard ANSI M58 MH ballast to make sure it starts but this does not guarantee 100% of the time the will start with different set up due to ballast and capacitor tolerances. Usually once the lamp starts and runs for a while, future starting is not an issue. We have heard that some use pulse start ballasts, which has higher starting voltage and has an igniter to assure lamp starting.

This is also true for the 400watt bulb, but you probally getaway with a standard ballast or an electronic ballast, but I would email the company and ask them if this bulb will work ok with there ballast. Starting voltage is the issue here. I've found a thread on reefcentral that recommends you have a PFO HQI ballast for this bulb. The bulb will burn brighter on the HQI ballast, many people claim the bulb is too blue.

Here's a couple of reviews of the bulb, note the lumens that the iwasaki puts out compared to the rest of the bulbs. Since the lumen output of the radium bulb is fairly low, 400 watters might be the way to go. Seems thats what most people are using.

http://www.animalnetwork.com/fish2/a...ct/default.asp
http://www.coralreefecosystems.com/ltg_bulb_color.htm
http://www.reefcentral.com/vbulletin...02/09/4/113997
http://www.reefcentral.com/vbulletin...02/09/4/116342

Sorry I could not find any reviews of the 250watt bulb...
Anyway when you mount your bulb make sure the bulbs nipple is up. Ushio claims there bulbs will burn brighter this way and is probally true for other manufactuers, since the nipple area provides more resistance to the arc.

Hope this helps
-Jimbo

[Minnreefer]

great questions, I have been thinking about "upgrading" to 20K but I don't want to buy all new ballast and such. I may get 1 bulb and try it on my standard PFO ballast.

Jon

[mojoreef]

Reed I would not recomend the 250 watt 20k. It does not seem to have the same bright whitesh color as the 400 and has an overal dark look. Why dont u like the 400, they do not give off the same heats as an 400 watt iwasaki if that is your worry.



On the firing of the bulbs I use regular ballasts and have no problems, they say if they fire the first time they will fire everytime, so I would say that pulse start ballasts are not required.

take care

mike

[Reedman]

Thanks for the responses everyone.

Mike, It's not that I dislike the 400W. Quite the contrary...I love the 400W, but I already have 2 250W MH ballasts that I am running. It would be much more cost effective to change just the bulbs and not the whole setup. But...since they don't give off the same cool blue look, I guess I will just have to enjoy the 10k bulbs until I can convince my better half (wife that is) that the additional cost is worth it .

I'll work on some VHO supplements instead.
-Reed

[jmbesq]

I've got two 250's that were 10k. I swiched one of them to 20 k and the half of the tank with the 10k looked yellow all of a sudden. the consensus from everyone who saw the tank burning the two different bulbs liked the 20k much better, colors were better

[MtnDewMan]

Reed,

I fired a 20000k Radium (250W) for about an hour total on my tank. I didn't give it near enough time to burn it, but didn't want to based on how it started out ... how blue it was. I didn't want to "ruin" a good thing I already had going. Here are a couple of pictures for you that I took then ... remember, the 20000k bulb is not burned in like it should be for a truer look.

Both pictures were taken on the same day ... the first one is my normal 10000k setup with actinics, the second one is a 10000k on the left, a 20000k on the right with no actinics.

[jmbesq]

MtnDewman,
I assume the 20ks appeared to blue in your tank? Thats the way the pic looked to me. Mine are Hamilton and they don't appearf quite as dark blue as yours did in the pic. Mine seem more like an ice blue.
Jim

[Reedman]

Thanks Chuck! That makes my decision easy. VHO supplements are on the list and 20K off. Maybe I will go with the 400W 20K some time in the future.

[MtnDewMan]

jmbesq ... yes, far too blue for me and that picture is true to what I was seeing. Like I said, if the bulb was burnt in for a longer period it probably would have crisped up a bit to a whiter color, but I wasn't going to chance it on my tank inhabitants for that period of time.

Reed ... hopefully you won't make a complete determination based on those pictures, only because of the lack of burn in time ... but glad I was able to help.