Lighting Questions

1mtnbkr · 12-27-2006, 01:55 PM

I just purchased a new 100 gallon tank on E-bay. The guy threw in some lights but I am not sure if they ar sufficient. Pleas give me your opinions.

It is a 100 Gallon (60x24x18) tank wigh canopy. There ar no lights mounted yet. I got one 400 watt MH light (no hood or reflector) and a VHO ballest rated for 128 watts (x2). The VHO has the mounting shckets but no bulbs.

What are the recommended mounting distances (from the water to the light)?

I don't want my coral selections to be limited because of insufficient light.

lcstorc · 12-27-2006, 02:04 PM

Well I am certainly not an expert of lighting but generally they recommend a mh bulb for every 2ft of tank. 400w is a big bulb though so if you mount it high enough it may cover most of the tank.

BoomerD · 12-27-2006, 02:08 PM

Well, you're going to need a LOT more light...MH reflectors are rated for a 2X2 area, so at the MINIMUM, you'll need ONE more, and your tank would benefit from having 3 instead of 2. What you COULD do, is use that 400 in the center, and a pair of 250's, one on each end. THAT would give you sufficient light for any coral or clam you want.
Heat may become an issue however. That's a LOT of heat being generated. A chiller will most likely be necessary with that combo. You COULD always sell that 400, and go with a pair of 250's. That should be enough light for MOST corals and clams, but the edges of the tank will be somewhat dimmer. That does make a nice place for those animals that prefer lower lighting however, so it's not necessarily a bad thing.

The VHO ballast is odd...VHO bulbs are 160 watts (72 inch) 110 watts, (48 inch) and 75 watts. (24 inch).

Metal halide mounting heights can range from 8" above the water, to 14" above the water. Intensity and spread will vary by height.

mps9506 · 12-27-2006, 07:02 PM

Without a reflector the mh bulb is not very efficient at all. For that size tank I'd recomend three halides either 250 or 400 watt with reflectors to maximize efficiency. You could gt away with two, but it would result in dark spots or dark edges in the tank, which isn't always a bad thing. Some like the look, and some organisms prefer the darker areas, especially some species of fish.

Ditto to what boomer said on the VHO ballast. Might need some more specs on that.

12-27-2006, 01:55 PM	#1 (permalink)
1mtnbkr Bryozoan Join Date: Sep 2006 Posts: 54 View Gallery Karma Komment	Lighting Questions I just purchased a new 100 gallon tank on E-bay. The guy threw in some lights but I am not sure if they ar sufficient. Pleas give me your opinions. It is a 100 Gallon (60x24x18) tank wigh canopy. There ar no lights mounted yet. I got one 400 watt MH light (no hood or reflector) and a VHO ballest rated for 128 watts (x2). The VHO has the mounting shckets but no bulbs. What are the recommended mounting distances (from the water to the light)? I don't want my coral selections to be limited because of insufficient light.

12-27-2006, 02:04 PM	#2 (permalink)
lcstorc Sunshine Reefer Join Date: Mar 2006 Location: Cocoa Fl Posts: 20,778 View Gallery Karma Komment Add yours!	Re: Lighting Questions Well I am certainly not an expert of lighting but generally they recommend a mh bulb for every 2ft of tank. 400w is a big bulb though so if you mount it high enough it may cover most of the tank. __________________ Peace LYNN You can't change the past but you can change how you view it. A reef tank is like a racecar. The faster you go the harder you crash. Lynn and Franks saltwater adventure Lynn's 20g clown tank Lynn's 90g of sunshine Every 60 seconds you spend upset is a minute of happiness you'll never get back. In Loving Memory Of Z 01/22/07 - 08/19/08

12-27-2006, 02:08 PM	#3 (permalink)
BoomerD Reef Shark Join Date: Nov 2003 Location: Northern California Posts: 5,637 View Gallery Karma Komment	Re: Lighting Questions Well, you're going to need a LOT more light...MH reflectors are rated for a 2X2 area, so at the MINIMUM, you'll need ONE more, and your tank would benefit from having 3 instead of 2. What you COULD do, is use that 400 in the center, and a pair of 250's, one on each end. THAT would give you sufficient light for any coral or clam you want. Heat may become an issue however. That's a LOT of heat being generated. A chiller will most likely be necessary with that combo. You COULD always sell that 400, and go with a pair of 250's. That should be enough light for MOST corals and clams, but the edges of the tank will be somewhat dimmer. That does make a nice place for those animals that prefer lower lighting however, so it's not necessarily a bad thing. The VHO ballast is odd...VHO bulbs are 160 watts (72 inch) 110 watts, (48 inch) and 75 watts. (24 inch). Metal halide mounting heights can range from 8" above the water, to 14" above the water. Intensity and spread will vary by height. __________________ Intelligence is not knowing all the answers, but knowing where and how to find them! www.google.com

12-27-2006, 07:02 PM	#4 (permalink)
mps9506 Totally stoked dude Join Date: Jan 2004 Location: Wilmington, NC Posts: 7,518 View Gallery Karma Komment	Re: Lighting Questions Without a reflector the mh bulb is not very efficient at all. For that size tank I'd recomend three halides either 250 or 400 watt with reflectors to maximize efficiency. You could gt away with two, but it would result in dark spots or dark edges in the tank, which isn't always a bad thing. Some like the look, and some organisms prefer the darker areas, especially some species of fish. Ditto to what boomer said on the VHO ballast. Might need some more specs on that. __________________ Mike "The Bandwith Bandit" Help Build Reefpedia Premium Membership Available! Support Reef Sanctuary Sponsors

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