Metal Halide Help needed

Engy Benjie · 15 Jun 2013 at 16:11

First off I don't know a lot about Metal Halide. I bought a second hand unit for my fish tank and a new 14k 150W arcadia bulb. When i turn the unit on the bulb just arcs and doesn't light up. I have no idea if it is a problem with the bulb or the unit? The bulb arrived with a yellowish gunk on the inside of the main chamber. Is that normal? Did i just buy the wrong type of bulb for the unit? Or is it a problem with the ballast or ignitor.

Any help would be greatly appreciated.

Nightglow · 15 Jun 2013 at 16:21

14k 150W arcadia bulb is a double ended Metal Halide lamp.

It will have a ballast, plus there could be a seperate ignitor somewhere on the fitting

More details about light fitting make/model please.

Engy Benjie · 15 Jun 2013 at 16:23

It is a double ended RX7 type bulb.

Engy Benjie · 15 Jun 2013 at 16:31

The lighting fixture is a aqua medic oceanlight 150W. I have stripped it down and it has a magnetic ballast and a electronic ignitor built into the unit. But i don't know enough about these units to work out if it is one of these components at fault or i just bought a faulty bulb. I could just buy a new ballast and ignitor off ebay. But i might just be wasting my money if they arn't at fault. The annoying thing is I can't test the bulb as i don't know anybody that has a unit.

Nightglow · 15 Jun 2013 at 16:31

Engy Benjie said:
It is a double ended RX7 type bulb.

I know that, mention it in my reply, what light fitting is it being used in?

Ignore this reply now.

Nightglow · 15 Jun 2013 at 16:41

There are high voltages in magnetic ballast,etc, so be careful poking around.

Long time since i worked with metal halide, but from memory the ballast should hum quietly when working.

Engy Benjie · 15 Jun 2013 at 16:44

The only sound it makes is a buzzing from the bulb arcing and the ignitor. I think i will just order new parts and cross my fingers.

Nightglow · 15 Jun 2013 at 16:54

You could go with the HQI Electronic Ballast, far superior over magnetic ballasts because they will drive any bulb of the rated wattage

See this link: http://www.3reef.com/forums/metal-h...st-question-aqua-medic-ocean-light-95785.html

A quick google shows aqua medic are using HQI electronic ballast in their fittings.

Don't know whether they offer the electronic ballast option as a upgrade for your fitting?

Engy Benjie · 15 Jun 2013 at 17:09

I have ordered a electronic ballast from ebay. Had a search of the same forum and a couple of people have done the same mod. Found the same model for £8 on ebay so hopefully this will solve my issues. and as you said should be superior.

Thanks for your help.

robfosters · 15 Jun 2013 at 17:11

My mate had one of those units and was advised to use AM aqualine bulbs with it.

I would be surprised though if it's a dodgy bulb.

Nightglow · 15 Jun 2013 at 17:15

Engy Benjie said:
I have ordered a electronic ballast from ebay. Had a search of the same forum and a couple of people have done the same mod. Found the same model for £8 on ebay so hopefully this will solve my issues. and as you said should be superior.

Thanks for your help.

Post back with a update please.

arknor · 15 Jun 2013 at 17:15

if the bulb just had a blue pulse when you turned it on then it's failing to ignite then the bulb was dead.

electronic ballasts are much better anyway, magnetic ones usually have a crappy humm and they can interfer with signals if they aren't properly shielded

Engy Benjie · 15 Jun 2013 at 17:59

arknor said:
if the bulb just had a blue pulse when you turned it on then it's failing to ignite then the bulb was dead.

electronic ballasts are much better anyway, magnetic ones usually have a crappy humm and they can interfer with signals if they aren't properly shielded

It just continually pulses blue when i turn it on.

Nightglow · 15 Jun 2013 at 18:23

Engy Benjie said:
The bulb arrived with a yellowish gunk on the inside of the main chamber. Is that normal?

Engy Benjie said:
It just continually pulses blue when i turn it on.

I am a idiot

, just read OP post again, missed the bit about yellow gunk,No not normal, BUT it could be a faulty ballast, causing lamp to blow,or failing to light up.
Or it could just be a faulty lamp, I would still replace ballast with electronic one, & try existing lamp, but you still might need a new lamp.

Engy Benjie · 17 Jun 2013 at 23:07

Awaiting the arrival of the new ballast from ebay, and have sent the bulb back to the company I bought it from. They seem to think the bulb is faulty as well. Oh well might not have needed the new ballast but as you have said its probably best I change it anyway.