watts per gallon.
- Thread starter oozy
- Start date
kelly
Member
Thanks to all,
I really enjoyed reading all the posts. I am not a watts per gallon fan either. I currently have 1 WPG, and have had no problems with thing growing and reproducing.
The color spectrum, intensity are what I feel are most important. I plan on adding an icecap 660 ballast and using 4 40 watt bulbs which will bump me up to a whopping 2 watts per gallon.
There are many beautiful tanks out there using 40 watt light flourescent lights on them, and they are doing quite well, including sps also.
Best of luck whatever lighting you are using, and forget WPG.
I really enjoyed reading all the posts. I am not a watts per gallon fan either. I currently have 1 WPG, and have had no problems with thing growing and reproducing.
The color spectrum, intensity are what I feel are most important. I plan on adding an icecap 660 ballast and using 4 40 watt bulbs which will bump me up to a whopping 2 watts per gallon.
There are many beautiful tanks out there using 40 watt light flourescent lights on them, and they are doing quite well, including sps also.
Best of luck whatever lighting you are using, and forget WPG.
ironreef
Member
you can ask most coral Guru's Intesity is most important. In reefs spectruim has little to do with accual coral color or growth. 6.5k 20k doesn't affect the corals as much as nutrition in the water. They may show different colors but intesity is MOST imortant this is why halides have more growth an color. I've seen small 29g tanks with 250hqi ,400w halides with nice grwoth of sps. It maybe over kill for anyother corals but imo halides are the best and cheapest lighting in anyting over 100g. if you want colorful fast growing sps,clams even softies.Key words are FAST Growing, Colorful Sps. I have some sps @6" under 250w 6.5k halides 3 110vho if I put it any lower they lose color. I have some sps thats on the bottom cuz if I put it up higher it losed color. SPS don't have the same lighting needs either.JME
[ November 16, 2001: Message edited by: Ironreef ]
[ November 16, 2001: Message edited by: Ironreef ]
adrian
Active Member
Totally agree with everyone. The way I see it, if your interested enough to set up a reef tank, you should be interested enough to research lighting and the way it works, not lean on a genral guide line invented back in the 80's that uses power consumption as a unit for measurment. Watts per gallon is a crap rule, and whoever keeps spreading it around should be forced to do our water changes fro eternity 
junkf15
Member
OK, Now we need to come up with some values that make sense…
I have also heard that 175 watt MH is adequate for 12 in deep tanks, 250 for 18in, and 400 for 24 in deep tanks or more. Can I explain that with LP/SF? I will treat the MH light as a point source, even though some of the bulbs are 12in long. Also for this calculation, I will assume that at each depth, the surface measured is flat, and I will assume that light emitted from less than a 45 degree angle is not strong enough to be considered, even though there is undoubtedly some useful light outside the 45 degree pyramid I will base my calculation on. I know not all tanks are as wide as they are deep, but for this calculation, I won't subtract out the surface area of the narrow tanks. I will also assume that a good reflector is being used, and thus make no attempt to subtract out the portion of the lumens produced by a particular bulb, which are emitted in other directions. Assuming we are using a single spectrum bulb, and that the bulb is emitting all of its energy in the PAR spectrum, we ought to be able to calculate some base line values. I will need data from others on this board to help refine this baseline, but with enough interest, we can come up with a useful rule of thumb for the light requirements for an average reef.
175 watt = 1.17x10^5 Lumens = 1.17e5 LP, over 12 in deep tank (12x12 bottom surface) = 1.17e5 LP/SF
250 watt = 1.67x10^5 Lumens = 1.67e5 LP over 18 in deep tank (18x18 bottom surface) = .74e5 LP/SF
400 watt = 2.67x10^5 Lumens = 2.67e5 LP over 24 in deep tank (24x24 bottom surface) = .67e5 LP/SF
All of these values have produced long term success by the experience of the members of this board, so it would seem that the minimum is somewhere below all of these values
It is debatable whether or not 175 is ok for 18in deep tanks, but most people agree that 175 is not enough for a 24 in deep tank so lets investigate the low end of the range.
175 watt = 1.17x10^5 Lumens = 1.17e5 LP over 24 in deep tank (24x24) = .29 LP/SF
So it would seem that the first data points we have are that anything less than 30x10^3 LP/SF is no enough light, and anything over 67x10^3 is enough. Let’s see if that passes the first common sense test…
All of the members of this board agree that NO lighting is insufficient for reefs, so ..
40 watt = .26x10^5 Lumens (assuming all PAR) = .26e5 LP = over any depth (48 long x 6 wide) = .13e5 LP/SF (13x10^3)
So even directly under the lights the LP/SF of NO bulbs, 13e3, is well below our minimum range, 30e3, making them inadequate for reef lighting, and that is consistent with the experience of the members of this board.
I don’t know what other reef keepers have found to be sufficient with respect to VHO bulbs and PC bulbs, but if those of you who use those bulbs can follow my calculations, and reproduce them for your lighting systems, with an observation about the success or lack of success you have had with your current LP/SF, that will help us refine the minimum LP/SF value for successful reef lighting!! My first bid is between 30e3 and 67e3 LP/SF, has anyone had long term success with something in between?
Thanks for the help,
I have also heard that 175 watt MH is adequate for 12 in deep tanks, 250 for 18in, and 400 for 24 in deep tanks or more. Can I explain that with LP/SF? I will treat the MH light as a point source, even though some of the bulbs are 12in long. Also for this calculation, I will assume that at each depth, the surface measured is flat, and I will assume that light emitted from less than a 45 degree angle is not strong enough to be considered, even though there is undoubtedly some useful light outside the 45 degree pyramid I will base my calculation on. I know not all tanks are as wide as they are deep, but for this calculation, I won't subtract out the surface area of the narrow tanks. I will also assume that a good reflector is being used, and thus make no attempt to subtract out the portion of the lumens produced by a particular bulb, which are emitted in other directions. Assuming we are using a single spectrum bulb, and that the bulb is emitting all of its energy in the PAR spectrum, we ought to be able to calculate some base line values. I will need data from others on this board to help refine this baseline, but with enough interest, we can come up with a useful rule of thumb for the light requirements for an average reef.
175 watt = 1.17x10^5 Lumens = 1.17e5 LP, over 12 in deep tank (12x12 bottom surface) = 1.17e5 LP/SF
250 watt = 1.67x10^5 Lumens = 1.67e5 LP over 18 in deep tank (18x18 bottom surface) = .74e5 LP/SF
400 watt = 2.67x10^5 Lumens = 2.67e5 LP over 24 in deep tank (24x24 bottom surface) = .67e5 LP/SF
All of these values have produced long term success by the experience of the members of this board, so it would seem that the minimum is somewhere below all of these values
It is debatable whether or not 175 is ok for 18in deep tanks, but most people agree that 175 is not enough for a 24 in deep tank so lets investigate the low end of the range.
175 watt = 1.17x10^5 Lumens = 1.17e5 LP over 24 in deep tank (24x24) = .29 LP/SF
So it would seem that the first data points we have are that anything less than 30x10^3 LP/SF is no enough light, and anything over 67x10^3 is enough. Let’s see if that passes the first common sense test…
All of the members of this board agree that NO lighting is insufficient for reefs, so ..
40 watt = .26x10^5 Lumens (assuming all PAR) = .26e5 LP = over any depth (48 long x 6 wide) = .13e5 LP/SF (13x10^3)
So even directly under the lights the LP/SF of NO bulbs, 13e3, is well below our minimum range, 30e3, making them inadequate for reef lighting, and that is consistent with the experience of the members of this board.
I don’t know what other reef keepers have found to be sufficient with respect to VHO bulbs and PC bulbs, but if those of you who use those bulbs can follow my calculations, and reproduce them for your lighting systems, with an observation about the success or lack of success you have had with your current LP/SF, that will help us refine the minimum LP/SF value for successful reef lighting!! My first bid is between 30e3 and 67e3 LP/SF, has anyone had long term success with something in between?
Thanks for the help,
junkf15
Member
I guess I was expecting it to be closer to the 454nm peak the high temp MH lights all target. Do corals prefer that freq (454) over others or is any light in the 400-700 spectrum going to keep most corals happy? I guess the point I'm getting at is this: Why pay extra for the 12000K or 20000K bulbs? I thought they were better for my critters, but was I mistken?
D
diatom
Guest
Junk~
Nice post about the PAR very well laid out.
I've been following an experiment done buy another online store and what they have found to date is that there is no significant diffrence in Stoney coral growth rates under 6500, 10000, and 20000 K bulbs. It seems that at least in this instance that the preference is simply in the eye of the beholder as it were.
Nice post about the PAR very well laid out.
I've been following an experiment done buy another online store and what they have found to date is that there is no significant diffrence in Stoney coral growth rates under 6500, 10000, and 20000 K bulbs. It seems that at least in this instance that the preference is simply in the eye of the beholder as it were.
kris walker
Active Member
I would say that different parts of the PAR spectrum are more important than others depending on the natural habitat of the coral in question. Corals that thrive in nature in shallow water will probably enjoy a broad range of the PAR. Others that thrive in nature in deeper water, like in forereefs, will probably not care about the redder end of the PAR, since it is basically non-existent at those depths. So with regard to SPS, where do they tend to grow the most? I know many thrive at shallow levels, and so they probably enjoy anything from red to blue.
sam
sam