250w MH 6inches from water surface?

Nem0 · 03/29/2008, 06:38 PM

Due to the height of my tank hood, I can only place my 250w MH light about 6 inches away from the water surface. Is this too low? I don't seem to be able to find any other way to raise the ligth safely.

Can I keep it this way? Will there be any problem with the corals? I keep mostly LPS. Many thanks.

ReefTECK · 03/29/2008, 06:46 PM

No that should be fine, mine are about that, maybe less actually. As long as you have the glass shield on them (if they are HQI) or if they are mougel socket bulb (mine are) will be fine. Just clean them regularly as they get salt creep very quickly.

ltz,
Andy

Nem0 · 03/29/2008, 07:29 PM

Thanks. There is tempered glass shield so the bulbs are protected.

Just worry that the light is too close to the water and heat up the water too quickly. Anyone else?

Nem0 · 03/29/2008, 10:54 PM

bump

Aquabucket · 03/29/2008, 10:56 PM

How deep is your tank? What type of bulbs?

Nem0 · 03/29/2008, 11:49 PM

The tank is 2.5ft deep, and I'm using BLV 20k, Pheneix 14k.

Nem0 · 03/30/2008, 12:58 AM

bump

downhillbiker · 03/30/2008, 01:01 AM

you should be ok. i have mine 6" off the water. i run open top, no glass to keep cooler, but it also lets more light in. i also have a couple of extra fans for summer time, but i also live in oregon, which has fairly cool summers, you may have to get a chiller if you live in florida. btw im running 760 watts on 72 gallon tank, and it does fine.

melev · 03/30/2008, 02:29 AM

It is too close. 9 to 12" off the water is what is recommended. Heat, risk of breakage (even the hot glass shield), PAR intensity due to proximity - all reasons why this bulb should not be so close to the water.

Additionally, you risk getting burned when reaching in your tank from time to time. It sounds like you have a big tank if it is 30" tall. I'd suggests a modified canopy, or cut holes in the top to elevate those lights a few more inches. They'll stick out the top, but you'll get the height you need.

tjone752000 · 03/30/2008, 05:17 AM

6 is too close for me. I run mine at 12, but thats just me.

Colin · 03/30/2008, 06:09 AM

I've had them closer than that. It's fine, especially on a 30" tank. If your tank gets hot then add a fan or two.

--Colin

03/29/2008, 06:38 PM	#1
Nem0 Registered Member Join Date: Mar 2004 Posts: 354	250w MH 6inches from water surface? Due to the height of my tank hood, I can only place my 250w MH light about 6 inches away from the water surface. Is this too low? I don't seem to be able to find any other way to raise the ligth safely. Can I keep it this way? Will there be any problem with the corals? I keep mostly LPS. Many thanks.

03/29/2008, 06:46 PM	#2
ReefTECK Registered Member Join Date: Apr 2007 Location: Iowa City, Iowa Posts: 901	No that should be fine, mine are about that, maybe less actually. As long as you have the glass shield on them (if they are HQI) or if they are mougel socket bulb (mine are) will be fine. Just clean them regularly as they get salt creep very quickly. ltz, Andy __________________ 2013 President of the Greater Iowa Reef Society www.iowareefs.org Current Tank Info: 120 Gallon Tank, 96 DIY LED's on 3 channels, 30gal sump/fuge, 4x2x0.5' & 40gal frag tank, SRO Ca rxr, GSA Kalk rxr, SRO 3000 skmr, Gen-X PCX40 Return, 2xMP40w's, 1xTunze 6101, 140lbs LR, SSB, SPS all the way!

03/29/2008, 10:56 PM	#5
Aquabucket Premium Member Join Date: Jun 2003 Location: Green Bay, Wi. Posts: 4,455	How deep is your tank? What type of bulbs? __________________ "Just a drop in the bucket"

03/30/2008, 01:01 AM	#8
downhillbiker Registered Member Join Date: Feb 2008 Location: Salt Lake City, Utah Posts: 2,831	you should be ok. i have mine 6" off the water. i run open top, no glass to keep cooler, but it also lets more light in. i also have a couple of extra fans for summer time, but i also live in oregon, which has fairly cool summers, you may have to get a chiller if you live in florida. btw im running 760 watts on 72 gallon tank, and it does fine. __________________ The friendliest GIANT you'll ever meet. Current Tank Info: 200g Marineland Deep Dimension (Lumenmax Reflectors/Dual PFO 400w/Radium 20K) and 2xFrag Tanks (One TEK T5 fixture and one MH, Galaxy/Phoenix) on same system w/100g sump w/6"x100g DSB, AquaC EV-1000 Skimmer, Reeflo Barracuda return pump

03/30/2008, 05:17 AM	#10
tjone752000 Registered Member Join Date: Dec 2007 Location: fairhaven ma Posts: 7	height 6 is too close for me. I run mine at 12, but thats just me.

03/29/2008, 07:29 PM	#3
Nem0 Registered Member Join Date: Mar 2004 Posts: 354	Thanks. There is tempered glass shield so the bulbs are protected. Just worry that the light is too close to the water and heat up the water too quickly. Anyone else?

03/29/2008, 10:54 PM	#4
Nem0 Registered Member Join Date: Mar 2004 Posts: 354	bump

03/29/2008, 11:49 PM	#6
Nem0 Registered Member Join Date: Mar 2004 Posts: 354	The tank is 2.5ft deep, and I'm using BLV 20k, Pheneix 14k.

03/30/2008, 12:58 AM	#7
Nem0 Registered Member Join Date: Mar 2004 Posts: 354	bump

03/30/2008, 02:29 AM	#9
melev Moved On Join Date: Sep 2002 Location: Ft Worth, Tx Posts: 43,217	It is too close. 9 to 12" off the water is what is recommended. Heat, risk of breakage (even the hot glass shield), PAR intensity due to proximity - all reasons why this bulb should not be so close to the water. Additionally, you risk getting burned when reaching in your tank from time to time. It sounds like you have a big tank if it is 30" tall. I'd suggests a modified canopy, or cut holes in the top to elevate those lights a few more inches. They'll stick out the top, but you'll get the height you need.

03/30/2008, 06:09 AM	#11
Colin Registered Member Join Date: May 2000 Location: Oklahoma City Posts: 848	I've had them closer than that. It's fine, especially on a 30" tank. If your tank gets hot then add a fan or two. --Colin