More Lighting Questions...Glass Top

starsbravo · 03/10/2006, 08:05 AM

I just recently went metal halide on my 36 gal bow front corner tank. I just started the aquarium in the anticipation that I will put corals in it. The light is a 150w 14,000K HQI. Its a beautiful light, but Im wondering if the glass top to the aquarium is refracting a lot of the light. Is this true? If so, would an acrylic top absorp more of the light . I would rather place the light on the aquarium with docking legs than to remove the glass top and suspend the light from the ceiling if at all possible. What are some suggestions?? Thanks

Blown 346 · 03/10/2006, 08:14 AM

The glass top will refract and cut down on the lightings intensity, plus the glass top will also hold in heat, and wont allow for proper gas exchange to take place. If the halide is too close to the glass top it can shatter from heat
I would actually ditch the glass top all together, and place the hailde atleast 6 inches off the water surface. If thehalide doesnt have a splash guard I would go even higher.

ChunksInClemson · 03/10/2006, 08:26 AM

I would say go at least 10 inches from the water. Maybe 14.

bertoni · 03/10/2006, 09:43 PM

A clean glass top will reduce the lighting by about 12% or so. Clear acrylic will aborb less, around 8%, I think. You can find numbers like these at tank-builders sites. Since it's a 150 W lamp, I would guess you might be fine with a glass top. I'd watch the temperature in the tank carefully, though, and make sure there's some gaps at the edges of the top to allow air into the tank.

I think my MH lamp is about 8" off the water (150 W over a 29g), with no top, though. 14" sounds like a lot of lost light to me.

03/10/2006, 08:05 AM	#1
starsbravo Registered Member Join Date: Feb 2004 Location: El Paso, TX Posts: 458	More Lighting Questions...Glass Top I just recently went metal halide on my 36 gal bow front corner tank. I just started the aquarium in the anticipation that I will put corals in it. The light is a 150w 14,000K HQI. Its a beautiful light, but Im wondering if the glass top to the aquarium is refracting a lot of the light. Is this true? If so, would an acrylic top absorp more of the light . I would rather place the light on the aquarium with docking legs than to remove the glass top and suspend the light from the ceiling if at all possible. What are some suggestions?? Thanks __________________ When will I finally get it right? Current Tank Info: 36 gal Reef & 90 gal rimless w/30 gal sump

03/10/2006, 08:26 AM	#3
ChunksInClemson Registered Member Join Date: Feb 2006 Location: Anderson, SC Posts: 824	I would say go at least 10 inches from the water. Maybe 14. __________________ Me to my brother-"Dude, you don't need to spend 75 dollars on a shirt! My brother to me-"Man, you just spent 100 dollars on some rocks" Me and him- "Laughs" Current Tank Info: 29g, a pair of true percs so far. Tank is newer!

03/10/2006, 09:43 PM	#4
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	A clean glass top will reduce the lighting by about 12% or so. Clear acrylic will aborb less, around 8%, I think. You can find numbers like these at tank-builders sites. Since it's a 150 W lamp, I would guess you might be fine with a glass top. I'd watch the temperature in the tank carefully, though, and make sure there's some gaps at the edges of the top to allow air into the tank. I think my MH lamp is about 8" off the water (150 W over a 29g), with no top, though. 14" sounds like a lot of lost light to me. __________________ Jonathan Bertoni

03/10/2006, 08:14 AM	#2
Blown 346 Registered Member Join Date: Apr 2004 Location: Rockford, Illinois Posts: 6,596	The glass top will refract and cut down on the lightings intensity, plus the glass top will also hold in heat, and wont allow for proper gas exchange to take place. If the halide is too close to the glass top it can shatter from heat I would actually ditch the glass top all together, and place the hailde atleast 6 inches off the water surface. If thehalide doesnt have a splash guard I would go even higher.