XM MH bulbs -Advice needed

[Sprattoo]

I am new to this whole Metal Halide thing.
I bought a great retro kit, 2x 175W magnetic ballasts, pulse start, all the goodies. With it I bought 2 175W 20K XM bulbs.

I got the thing wired, built a box to hang the kit in, fired 'em up. they were way too blue, but the tank still looked nice and the light was potent.

So upon reworking the plug-in setup and rigging a heavy duty timer for the lamps I unplugged and plugged the ballasts. Unplugged then re-plugged a couple seconds later. The bulbs began to try to start, but as they were, a bright red hot metal bit fell off inside the bulb and they weren't starting. I unplugged both only to discover they had both "dropped" this bit of hot metal inside the lamp.

I let them cool, tried to replug them in... nothing happened, the bulbs now rattle about a bit.

I'm thinking my bulbs are blown (after only 4 days of use)
I would truly like some advice on what brand of bulb to get to replace these. Hello lights lists the 175W 10,000K - Ushio for $65 each.

I am going to see if Hello lights might replace these bulbs. the plugging and unplugging would be nothing more than would have happened in a brief power dip, but I don't think I want anymore XM's, and I want a whiter light.

Any advice would be REALLY helpful.


ALSO, I have the bottom of my light box hanging over the tank (75 G) open. the bulbs themselves are about 12-13 inches above the surface, the bottom of the "light box" more like 5" from the surface.

Should I cover the bottom of the box with anything? I'm pretty concious about water splashes and fizzing at the surface. But if I still should cover the bottom of my box, what would be acceptable? It seems plexi would warp,esp. with the heat, glass maybe, but it would be a hassle to install securely.

again all suggestions appreciated

 

[Anonymous]

Your bulbs are probably plenty high enough so that you don't have to worry about splash. My 175's are about 8" off the water surface and I have never had a problems.

As for replacement lamps, I personally like 10K bulbs by Ushio. AB's 10 k's are pretty nice too. It really is just personal preferance.

Most folks think that the 20K's just aren't bright enough unless they are the 400's, then they look alot better.

Louey

 

[Sprattoo]

Is this a common problem with MH lamps?

If they go off then on quickly would any bulb have fried?

should I expect my $$ back or bulb replacement?

 

[Anonymous]

I have never had a bulb fail in spite of frequent on/off.

I would ask for replacment bulbs for sure.

Louey

 

[Insider]

One easy way to test if bulbs are blown, there should not be any resistance between the contacts on the bulb. just use any cheap multi meter to test it. if it shows a open circuit, then your bulbs are blown.

Oh one thing, you prob know this, don't touch the bulb glass with bare fingers, the oils that leaves finger prints will over heat the bulb, reducing their life...

 

[Sprattoo]

yes I did know about the touching the glass thing.... but I don't think its common knowlege, and I didn't see or hear anything about that during the purchase.

I do like hellolights.com though and they replaced the bulbs. I paid an extra $15 and had them ship me 2 Ushio 10K 175W bulbs instead of the XM 20K's. They also were helpfull and verified what you have said that an on off on should not have blown the bulbs, they just wanted to know that I was using their retro kit and there was no prob. They charged me for new bulbs but will credit me for the old blown ones as soon as they get there.

I'm happy, good price, good customer service, and they actually talk with you and will offer advice or try to help you out.
this is the third order I have gotten from them and as I am considering a nano project I have them in mind for future lighting, bulbs etc..