Giesemann - Crack/Snap when fixture turns off

Amazon4 · 04/11/2008, 10:22 PM

We have a Giesemann 72" fixture (3 x 250mh). It's roughly a year old. Bought it from a fellow reefer who decided his 180 was too much for him after setting it up for about 6 months.

Anyhow, about 15 minutes or so after the light(s) is shut off, there's a rather load snap/crack sound. The first time I heard this I thought our tank (180) just let go. Then we noticed the pattern of it happening after lights out.

We've called the US Geisemann rep and left messages. No response so far.

Also, the lights are very noisey at start-up (bwanggggg!).

I must say, I thought we were buying one of the best lights out there. So far I'm not impressed.

Does any one else have this kind of problem when their lights cool off? I'm wondering how unusual this is. We have two other 250mh fixtures on two other tanks and they don't do this.

TIA

ACBlinky · 04/12/2008, 10:14 AM

My MH bulbs do make a bit of a sound when they turn on (fans are much louder though), and they do snap crackle and pop sometimes as they cool down. AFAIK it's fairly normal -- mine have been doing this for 18 months, nothing's blown up so far

snorvich · 04/12/2008, 10:31 AM

thermal expansion and contraction causes this. I get it too on heat and cooling of my lights. In my case it is fairly obvious noise because I have a canopy

Amazon4 · 04/13/2008, 12:33 PM

Thanks folks. I guess it's just unnerving to hear a loud crack from a room with a 180 in it

04/11/2008, 10:22 PM	#1
Amazon4 Premium Member Join Date: Nov 2006 Location: Arlington, MA Posts: 690	Giesemann - Crack/Snap when fixture turns off We have a Giesemann 72" fixture (3 x 250mh). It's roughly a year old. Bought it from a fellow reefer who decided his 180 was too much for him after setting it up for about 6 months. Anyhow, about 15 minutes or so after the light(s) is shut off, there's a rather load snap/crack sound. The first time I heard this I thought our tank (180) just let go. Then we noticed the pattern of it happening after lights out. We've called the US Geisemann rep and left messages. No response so far. Also, the lights are very noisey at start-up (bwanggggg!). I must say, I thought we were buying one of the best lights out there. So far I'm not impressed. Does any one else have this kind of problem when their lights cool off? I'm wondering how unusual this is. We have two other 250mh fixtures on two other tanks and they don't do this. TIA

04/12/2008, 10:14 AM	#2
ACBlinky Premium Member Join Date: May 2005 Location: Peterborough, ON, Canada Posts: 4,954 Blog Entries: 20	My MH bulbs do make a bit of a sound when they turn on (fans are much louder though), and they do snap crackle and pop sometimes as they cool down. AFAIK it's fairly normal -- mine have been doing this for 18 months, nothing's blown up so far __________________ "The cure for anything is salt water: sweat, tears, or the sea." - Isak Dinesen Current Tank Info: 150g mixed reef, 30g sump/refugium, LED lighting, 100lbs LR, coral beauty, flame angel, blue & yellow tangs, gobies, damsels, 6-line wrasse, lawnmower blenny, dottyback, clown pair, rabbitfish, shrimp, crabs, CUC.

04/12/2008, 10:31 AM	#3
snorvich Team RC member Join Date: Aug 2005 Location: Outlander Posts: 40,953 Blog Entries: 46	thermal expansion and contraction causes this. I get it too on heat and cooling of my lights. In my case it is fairly obvious noise because I have a canopy __________________ Warmest regards, ~Steve~

04/13/2008, 12:33 PM	#4
Amazon4 Premium Member Join Date: Nov 2006 Location: Arlington, MA Posts: 690	Thanks folks. I guess it's just unnerving to hear a loud crack from a room with a 180 in it