How much light?

hardimanm · 06/19/2009, 01:57 PM

Is there a "magic number" for how much light needs to be in a standard saltwater tanks. And how about with corals in it? What K rating is best and is the actinic light important?

I really like the look of the branching corals. I guess im talking about sps corals? How much light would i need for them?

Thanks so much
Michael

cwbhawk · 06/19/2009, 02:03 PM

You would definately need Metal Halides or at least t5's for sps, and yes the actinic is just as important as the daylight. The K rating on daylight and Actinic bulbs can sometimes aid in coral growth, but I don't usually notice, so I think that the Kelvin rating is pretty much just what you prefer, as long as it is produced for aquarium use. There is usually a certain watt/gallon ratio that people follow for keeping sps corals, but I have never kept an sps coral so Im not sure what that number is

WaterKeeper · 06/19/2009, 02:16 PM

For a 42 gallon the T-5's will do nicely. The best system is to use a balance of some actinic, mainly daylight (5500-9,000K) and some high K lamps if you like a blue look to the tank. MH are fine, but probably not needed, on a tank that small. The T-5's should support most corals and, if you have a especially demanding coral, just placing it closer to the lights will usually do.

thedoctor06 · 06/19/2009, 02:29 PM

It's my understanding the actinic lights are mainly for our viewing pleasure, as they have low PAR and only make the corals appear to flouresce

hardimanm · 06/19/2009, 03:22 PM

how much watts per gallon though?

Rangereefer · 06/19/2009, 03:25 PM

Don't fall into the watts/gallon trap thats a mythical rating. Quality and intensity of the light are far more important than a watts/gallon rating

hardimanm · 06/19/2009, 03:50 PM

Thanks. Just did not want to get a fixture and find out that it does not have enough watts to grow the corals

cveverly · 06/19/2009, 05:41 PM

What are the dimensions of the tank?

hardimanm · 06/19/2009, 06:32 PM

It is a hex aquarium so the dimensions are kind of funny. It is 22" from one side to the other across the top and bottom (one side of the hex to the other), from point to point is 25". From top to bottom it is 23.5". Each hex panel is 12.25" by 23.5.

cveverly · 06/19/2009, 06:52 PM

I was afraid of that. In my opinion it is going to be very hard to get a T5 setup to work. I feel you will need a Metal Halide fixture on that tank.

EDIT: I am no expert on lighting but I assume you would need around 250 watts of MH.

E.intheC · 06/19/2009, 07:19 PM

Quote:

Originally posted by Rangereefer
Don't fall into the watts/gallon trap thats a mythical rating. Quality and intensity of the light are far more important than a watts/gallon rating

That's a great first post!

To Reef Central

Rangereefer · 06/19/2009, 09:47 PM

Thanks E.intheC

hardimanm -- like cveverly says you are probably going to have to go MH based on the dimensions. T5s come in a 20" length but I think there is only a single manufacturer so your gonna be limited in the color choices in a 20". A halide would probably work best to penetrate the 23.5" depth also. You'll also get a really nice shimmer effect. If your tank has a hood make sure you have adequate venting and airflow as the MH is gonna increase heat alot. As far as wattage I'm really not sure. I'd assume a 250 shouldn't cook the corals.

You did mentioned that you like the branching type of corals. I would assume you are refering to the SPS (small Polyp Stony) corals. You may want to check out the sub forums dedicated to each type of coral to check out what there is. SPS corals are by most accounts the most advanced and demanding corals to keep. I thought I wanted SPS corals too until I checked out some of the LPS's and soft corals. They are the most light and flow demanding corals out there. MH is probably the most economical option at this time for your situation for the forseeable future.

rudipez · 06/19/2009, 11:06 PM

I believe it is 4-5 watts per gallon. It all depends on what you are trying to keep in your tank. With MH's , T-5 or LEDs you can keep pretty much anything.

20K is much more blue in the light spectrum and can cause the corals to grow slower. I really like the look of the 20k.

hardimanm · 06/20/2009, 08:45 AM

Ok...so MH huh. Ouch. They are quite pricey i see. Would i need the same intensity with soft corals or LPS?

cveverly · 06/20/2009, 08:49 AM

If you watch the classifies or local group you can find metal halide lights in the 150 dollar range.

You could keep softies with small T5 lamps but the real problem is the depth of your tank.

hardimanm · 06/20/2009, 08:53 AM

okay... so seeing i need a 250 watt. what brands would you think best? and is it better to have pendant or one that sits on top of the tank?

Rangereefer · 06/20/2009, 10:59 AM

MH has to be elevated around 6" from the surface of the water if I remember right.

Another thing to Remember that you can have stuff shipped too. I live in the middle of nowhere and I was able to have a 3ft fixture shipped to me for around 25 bucks from PA. Watch the equipment forums here as well there are some great deals just remember odds are the bulbs will have to be replaced unless the seller advises how long they have had it for.

Pendant will give you the most options as far as low prices go as I don't even know if any manufacturers make 20" fixtures for MH.

lurch · 06/20/2009, 11:03 AM

For your hex tank I think a pendant would look cool. Plus it would probably be hard to get a light with legs on it to sit right on a hexagon tank.

rudipez · 06/20/2009, 05:18 PM

Yeah i would get a pendent but the only thing i do not like about them is that they have a gap that blinds you if you don't have a canopy.

You can find them really cheep on E-bay, here on RC, or even Craigslist. Just be patient and wait till you see what your looking for at the price you can handle!!

i built a canopy for my tank so i can view my tank while sitting down without being blinded from the lights.

06/19/2009, 01:57 PM	#1
hardimanm Registered Member Join Date: May 2009 Location: Madison, Alabama Posts: 207	How much light? Is there a "magic number" for how much light needs to be in a standard saltwater tanks. And how about with corals in it? What K rating is best and is the actinic light important? I really like the look of the branching corals. I guess im talking about sps corals? How much light would i need for them? Thanks so much Michael

06/19/2009, 02:03 PM	#2
cwbhawk Junior at Iowa State Join Date: Nov 2008 Location: Cedar Falls, Iowa Posts: 148	You would definately need Metal Halides or at least t5's for sps, and yes the actinic is just as important as the daylight. The K rating on daylight and Actinic bulbs can sometimes aid in coral growth, but I don't usually notice, so I think that the Kelvin rating is pretty much just what you prefer, as long as it is produced for aquarium use. There is usually a certain watt/gallon ratio that people follow for keeping sps corals, but I have never kept an sps coral so Im not sure what that number is __________________ I am a nice shark, not a mindless eating machine. If I am to change this image I must first change myself. Fish are friends not food. Current Tank Info: 20 gallon tank that I move back and forth from school with me!

06/19/2009, 02:16 PM	#3
WaterKeeper Bogus Information Expert Join Date: Oct 2000 Location: SW Ohio Posts: 16,147	For a 42 gallon the T-5's will do nicely. The best system is to use a balance of some actinic, mainly daylight (5500-9,000K) and some high K lamps if you like a blue look to the tank. MH are fine, but probably not needed, on a tank that small. The T-5's should support most corals and, if you have a especially demanding coral, just placing it closer to the lights will usually do. __________________ "Leading the information hungry reefer down the road to starvation" Tom Current Tank Info: 130 Now out of service and a 29

06/19/2009, 03:25 PM	#6
Rangereefer Registered Member Join Date: Apr 2009 Location: Virginia, Minnesota Posts: 55	Don't fall into the watts/gallon trap thats a mythical rating. Quality and intensity of the light are far more important than a watts/gallon rating Last edited by Rangereefer; 06/19/2009 at 03:34 PM.

06/19/2009, 02:29 PM	#4
thedoctor06 Registered Member Join Date: Oct 2007 Location: Centennial, CO Posts: 188	It's my understanding the actinic lights are mainly for our viewing pleasure, as they have low PAR and only make the corals appear to flouresce

06/19/2009, 03:22 PM	#5
hardimanm Registered Member Join Date: May 2009 Location: Madison, Alabama Posts: 207	how much watts per gallon though?

06/19/2009, 03:50 PM	#7
hardimanm Registered Member Join Date: May 2009 Location: Madison, Alabama Posts: 207	Thanks. Just did not want to get a fixture and find out that it does not have enough watts to grow the corals

06/19/2009, 05:41 PM	#8
cveverly Registered Member Join Date: Mar 2005 Location: Port Clinton, Oh Posts: 1,470	What are the dimensions of the tank?

06/19/2009, 06:32 PM	#9
hardimanm Registered Member Join Date: May 2009 Location: Madison, Alabama Posts: 207	It is a hex aquarium so the dimensions are kind of funny. It is 22" from one side to the other across the top and bottom (one side of the hex to the other), from point to point is 25". From top to bottom it is 23.5". Each hex panel is 12.25" by 23.5.

06/19/2009, 06:52 PM	#10
cveverly Registered Member Join Date: Mar 2005 Location: Port Clinton, Oh Posts: 1,470	I was afraid of that. In my opinion it is going to be very hard to get a T5 setup to work. I feel you will need a Metal Halide fixture on that tank. EDIT: I am no expert on lighting but I assume you would need around 250 watts of MH.

06/19/2009, 09:47 PM	#12
Rangereefer Registered Member Join Date: Apr 2009 Location: Virginia, Minnesota Posts: 55	Thanks E.intheC hardimanm -- like cveverly says you are probably going to have to go MH based on the dimensions. T5s come in a 20" length but I think there is only a single manufacturer so your gonna be limited in the color choices in a 20". A halide would probably work best to penetrate the 23.5" depth also. You'll also get a really nice shimmer effect. If your tank has a hood make sure you have adequate venting and airflow as the MH is gonna increase heat alot. As far as wattage I'm really not sure. I'd assume a 250 shouldn't cook the corals. You did mentioned that you like the branching type of corals. I would assume you are refering to the SPS (small Polyp Stony) corals. You may want to check out the sub forums dedicated to each type of coral to check out what there is. SPS corals are by most accounts the most advanced and demanding corals to keep. I thought I wanted SPS corals too until I checked out some of the LPS's and soft corals. They are the most light and flow demanding corals out there. MH is probably the most economical option at this time for your situation for the forseeable future.

06/19/2009, 11:06 PM	#13
rudipez Registered Member Join Date: Nov 2006 Location: Elmwood Park, Il. Posts: 175	I believe it is 4-5 watts per gallon. It all depends on what you are trying to keep in your tank. With MH's , T-5 or LEDs you can keep pretty much anything. 20K is much more blue in the light spectrum and can cause the corals to grow slower. I really like the look of the 20k.

06/20/2009, 08:45 AM	#14
hardimanm Registered Member Join Date: May 2009 Location: Madison, Alabama Posts: 207	Ok...so MH huh. Ouch. They are quite pricey i see. Would i need the same intensity with soft corals or LPS?

06/20/2009, 08:49 AM	#15
cveverly Registered Member Join Date: Mar 2005 Location: Port Clinton, Oh Posts: 1,470	If you watch the classifies or local group you can find metal halide lights in the 150 dollar range. You could keep softies with small T5 lamps but the real problem is the depth of your tank.

06/20/2009, 08:53 AM	#16
hardimanm Registered Member Join Date: May 2009 Location: Madison, Alabama Posts: 207	okay... so seeing i need a 250 watt. what brands would you think best? and is it better to have pendant or one that sits on top of the tank?

06/20/2009, 10:59 AM	#17
Rangereefer Registered Member Join Date: Apr 2009 Location: Virginia, Minnesota Posts: 55	MH has to be elevated around 6" from the surface of the water if I remember right. Another thing to Remember that you can have stuff shipped too. I live in the middle of nowhere and I was able to have a 3ft fixture shipped to me for around 25 bucks from PA. Watch the equipment forums here as well there are some great deals just remember odds are the bulbs will have to be replaced unless the seller advises how long they have had it for. Pendant will give you the most options as far as low prices go as I don't even know if any manufacturers make 20" fixtures for MH.

06/20/2009, 11:03 AM	#18
lurch Registered Member Join Date: Sep 2003 Location: Gilbert, AZ Posts: 483	For your hex tank I think a pendant would look cool. Plus it would probably be hard to get a light with legs on it to sit right on a hexagon tank.

06/20/2009, 05:18 PM	#19
rudipez Registered Member Join Date: Nov 2006 Location: Elmwood Park, Il. Posts: 175	Yeah i would get a pendent but the only thing i do not like about them is that they have a gap that blinds you if you don't have a canopy. You can find them really cheep on E-bay, here on RC, or even Craigslist. Just be patient and wait till you see what your looking for at the price you can handle!! i built a canopy for my tank so i can view my tank while sitting down without being blinded from the lights.