Do 400 Watt MH Bulbs (screw-in) Have Same Diameter Bases as 250's?

Kengar · 08/08/2011, 01:09 PM

I picked up a few used Lumenarc reflectors. The person I bought them from was using 400 watt metal halide bulbs (radium's I believe). I want to use 250's instead (heat and electric bill). Will 250's fit, or do I need to replace the socket assemblies?

Thanks

mattiej · 08/08/2011, 02:15 PM

No. Most all MH have a mogul base regardless of wattage. This is assuming SE lamps.

Kengar · 08/08/2011, 06:22 PM

Yes, single-ended bulbs, with mogul base. So really, the question boiled down to being whether the mogul base is the same as between 250's and 400's. (I'm guessing from your response that they are.)

By "No," I am assuming you are referring to the second half of my compound question ("do I need to replace the socket assemblies") -- my bad at that! -- and that the answer to the first half of the question ("will 250's fit") is "yes." Correct?

allsps40 · 08/08/2011, 07:19 PM

Yes 250 and 400 SE Mogul base are the same size so are 25 and 400 DE bulbs all you need to do is change that ballast for the watt bulb you are using.

mattiej · 08/08/2011, 07:24 PM

Sorry but yes all mogul bases are the same size, Mogul is mogul. The differences are with the ballast used to power the lamps, the internal mechanisms of the lamp, and the length of the lamps.

SPS is correct, you do not have to change out the mogul just make sure to match ballast to lamp wattage.

James77 · 08/08/2011, 08:38 PM

175s, 250s, 400's all have the same bases.

08/08/2011, 01:09 PM	#1
Kengar Registered Member Join Date: Sep 2000 Location: Gaithersburg, MD (D.C. Metro Area) Posts: 1,970	Do 400 Watt MH Bulbs (screw-in) Have Same Diameter Bases as 250's? I picked up a few used Lumenarc reflectors. The person I bought them from was using 400 watt metal halide bulbs (radium's I believe). I want to use 250's instead (heat and electric bill). Will 250's fit, or do I need to replace the socket assemblies? Thanks __________________ Resident Patent Attorney

08/08/2011, 02:15 PM	#2
mattiej Registered Member Join Date: Feb 2004 Location: Thorndale, PA Posts: 495	No. Most all MH have a mogul base regardless of wattage. This is assuming SE lamps. __________________ I don't need to eat as long as my tanks look good! Current Tank Info: 200 SPS, 1200 Scyliorhinus retifer and S. canicula, Shark Lagoon

08/08/2011, 06:22 PM	#3
Kengar Registered Member Join Date: Sep 2000 Location: Gaithersburg, MD (D.C. Metro Area) Posts: 1,970	Yes, single-ended bulbs, with mogul base. So really, the question boiled down to being whether the mogul base is the same as between 250's and 400's. (I'm guessing from your response that they are.) By "No," I am assuming you are referring to the second half of my compound question ("do I need to replace the socket assemblies") -- my bad at that! -- and that the answer to the first half of the question ("will 250's fit") is "yes." Correct? __________________ Resident Patent Attorney

08/08/2011, 07:19 PM	#4
allsps40 Registered Member Join Date: Aug 2010 Location: Arizona Posts: 4,627	Yes 250 and 400 SE Mogul base are the same size so are 25 and 400 DE bulbs all you need to do is change that ballast for the watt bulb you are using. __________________ __________ Current Tank Info: Past reef tanks: 20H softy, 29G mixed reef, 55G mixed reef, 40B sps dominant mixed reef and 75G sps dominant mixed reef. No tank currently

08/08/2011, 07:24 PM	#5
mattiej Registered Member Join Date: Feb 2004 Location: Thorndale, PA Posts: 495	Sorry but yes all mogul bases are the same size, Mogul is mogul. The differences are with the ballast used to power the lamps, the internal mechanisms of the lamp, and the length of the lamps. SPS is correct, you do not have to change out the mogul just make sure to match ballast to lamp wattage. __________________ I don't need to eat as long as my tanks look good! Current Tank Info: 200 SPS, 1200 Scyliorhinus retifer and S. canicula, Shark Lagoon

08/08/2011, 08:38 PM	#6
James77 Registered Member Join Date: Aug 2005 Location: Rhode Island Posts: 8,158	175s, 250s, 400's all have the same bases. __________________ Jim Current Tank Info: 120g Mixed Reef and 75g Freshwater