Radium bulb run position

[Yogre]

When I was recently doing my annual MH bulb replacement, I actually took time to read the Radium documentation. The literature said the nipple inside the bulb should point basically straight up.

Many of y'all probably knew this but it was news to me. :o

My problem is that two of the three bulbs when fully screwed in are not anywhere near fully vertical. If I loosen them enough that the nipple is vertical, the bulb is very loose in the socket.

Anyone know how to fix this issue? Bulbs are 250W mogul base.

[ganjero]

Yes, flip the socket (unscrew the socket, turn it around and screw in again). You should be safe if the nipple is anywhere between 11 and 1 o'clock but it shouldn't be too hard to have it at 12.

[d2mini]

one of mine point up, two point down.
What's the difference which way it points?

[Yogre]

Yes, flip the socket (unscrew the socket, turn it around and screw in again). You should be safe if the nipple is anywhere between 11 and 1 o'clock but it shouldn't be too hard to have it at 12.

I was afraid you were going to say that. I'm running a Lumen Max 2 from Sunlight Supply, and the damn socket is bolted to a metal "L" with some sort of bolt that doesn't even have wrench flats on it. I'll have to completely disassemble the fixture and drill the bracket to rotate the socket.

[Yogre]

one of mine point up, two point down.
What's the difference which way it points?

Dennis, honestly I'm not sure aside from the fact that Radium does describe that specific nipple up position in the literature that came with the bulbs.

I have a feeling that the position has an impact on bulb color, as the bulb that is correctly oriented is burning just a bit bluer than the other two.

I was inclined to dismiss it as old eyes or an illusion from having more light-colored corals in the bluer end of the tank, but my wife can see it too.

[ganjero]

I was afraid you were going to say that. I'm running a Lumen Max 2 from Sunlight Supply, and the damn socket is bolted to a metal "L" with some sort of bolt that doesn't even have wrench flats on it. I'll have to completely disassemble the fixture and drill the bracket to rotate the socket.

Can you just flip the metal assembly inside the socket? I believe you can.



I have a feeling that the position has an impact on bulb color, as the bulb that is correctly oriented is burning just a bit bluer than the other two.


This is the reason the manufacturer have given.

[Yogre]

Can you just flip the metal assembly inside the socket? I believe you can.


Hmmm, I'll have to look at it again. It looked to me like the socket was bolted to the L bracket, which is then screwed into the outside frame of the fixture. The L bracket supports the socket. The idea is to be able to loosen a couple of screws and slide the bracket/socket assembly back and forth, so that the fixture can accommodate either a 250W or 400W bulb.

I knew I should have bought the Hamilton fixture. :lol:

[Yogre]

Dennis, honestly I'm not sure aside from the fact that Radium does describe that specific nipple up position in the literature that came with the bulbs.

I have a feeling that the position has an impact on bulb color, as the bulb that is correctly oriented is burning just a bit bluer than the other two.

I was inclined to dismiss it as old eyes or an illusion from having more light-colored corals in the bluer end of the tank, but my wife can see it too.

It's a subtle effect, but it's definitely there. You'd never see it with your actinics on. I don't run any supplementation with my Radiums.

[ganjero]

Hmmm, I'll have to look at it again. It looked to me like the socket was bolted to the L bracket, which is then screwed into the outside frame of the fixture. The L bracket supports the socket. The idea is to be able to loosen a couple of screws and slide the bracket/socket assembly back and forth, so that the fixture can accommodate either a 250W or 400W bulb.

I knew I should have bought the Hamilton fixture. :lol:

I am referring to the metal part inside the socket's ceramic casing, where the bulb actually screws in.

[Yogre]

I am referring to the metal part inside the socket's ceramic casing, where the bulb actually screws in.

Oh! Now I see what you're saying! I'll have a look tomorrow morning when the lights are off and cool, and report back.

Thanks, ganjero!

[d2mini]

Hmmm, I'll have to look at it again. It looked to me like the socket was bolted to the L bracket, which is then screwed into the outside frame of the fixture. The L bracket supports the socket. The idea is to be able to loosen a couple of screws and slide the bracket/socket assembly back and forth, so that the fixture can accommodate either a 250W or 400W bulb.

I knew I should have bought the Hamilton fixture. :lol:

My fixture is Hamilton. ;)
I don't see a color diff but I do run T5's too.
What I do see is that I have more shimmer under the one pointing up.

[tkeracer619]

You can bend the middle contact out and not screw the bulb in all the way. It doesn't need to be cranked down and bottomed out.

[Yogre]

You can bend the middle contact out and not screw the bulb in all the way. It doesn't need to be cranked down and bottomed out.

Cool, now I've two things to look at in the morning! I do in fact have the bulbs bottomed out.

Thanks guys!

[Yogre]

My fixture is Hamilton. ;)
I don't see a color diff but I do run T5's too.
What I do see is that I have more shimmer under the one pointing up.

Yeah, of course I buy the fixture that's not easily adjustable. :hmm5: To add insult to injury, Sunlight Supply seems to have gotten out of the aquarium fixture business, so how readily available would parts be? Story of my life! :lol:

[d2mini]

I did what was recommended above, just pulled on the tab inside so I didn't have to screw the bulb in quite as far.
I still don't see a difference. lol
Maybe more shimmer but probably not. My flow is variable so I think that's why the shimmer is changing. ;)

[tkeracer619]

Maybe we are just crazy...

http://www.advancedaquarist.com/2002/3/review

[ganjero]

Maybe we are just crazy...

http://www.advancedaquarist.com/2002/3/review

I have done this just following manufacturers recommendations...if I remember correctly it has to do with the nipple becoming a cold spot when facing downwards. This causes the accumulation of metals at the nipple and they stop entering the arc tube causing the "shift" in spectrum. Heat rises and having the nipple up will keep it hot.
That said it is hard to imagine something inside a mh bulb can become a coldspot but bulb manufacturers have more knowledge on the matter than me. :p

[d2mini]

Heat rises and having the nipple up will keep it hot.


I love this thread. :D

[tkeracer619]

Yeah, google that! :lol:

[Yogre]

Hot nipples, who would have known?

Dennis, any chance you could turn off your actinics to see if there's any difference?

In any event, I'm gonna see if I can rotate my nipples in the morning.

There, top that without getting infractionated! :lol:

[d2mini]

There, top that without getting infractionated! :lol:

How about you come over and rotate my nipples? :lol:

Actually, I already rotated mine before i checked without T5's on.
So can you not just pull up on that tab inside????

[tkeracer619]

If you need better contact bend the tab a bit. The bulb doesn't need to be bottomed out into the socket. Its ok to back it off a bit.

[Aquatron]

I looked at my nipples one points up one over to the side....kind of off set:hmm5:

[Yogre]

Well, I now have nipple rotation. :crazy1:

Did it make any difference? I'm not sure. It does look just a touch bluer on the side of the tank where the bulbs needed to be rotated. Of course it's also possible I'm guilty of expectation bias, and I'm seeing what I want to see. I'll be curious to see if my wife can tell any difference when she gets home.

Tkeracer619, I ended up using your suggestion to bend the tab up. The bulb is a touch loose in the socket but there's obviously enough contact or the bulb wouldn't light.

Ganjero, when I had the bulb out I could see 4 small screws in the socket. Two obviously were to hold the socket to the L bracket in the back. The other two may well be to allow adjustment of the metal part within the socket. Next time I replace the bulbs I will take the fixture off the tank and experiment with them.

Thanks everyone for your help...and a little levity too!! :lol: