MH Lighting Upgrade
JerseyReef
You'll get many different opinions on this subject, so I'll give you
mine...by no means is this the rule, just IMO
The first thing you need to do is read this article by Sanjay Joshi/Dave
Morgan
http://www.personal.psu.edu/faculty/s/b/sbj4/aquarium/ballast%20comparison/b
allast-comparison.html I'm sorry if you've read this article already, but
it's a great article when it comes to comparing different bulb/ballast
combo's.
You have a ~52 gal tank to work with here, you'll be adding a DSB, right? So
that will add ~4" - 6" to the bottom of the tank giving you ~ 14"-12" from
the top of the tank. 250's will give you excellent light penetration with
this type of depth. However, your length is 4'. You can get good light
spread from 2 bulbs at best, 3 would be better here. You could get some
shadowing from two, depending on how you mount them.
You said that you wanted to keep high light species? By this did you mean
SPS? or something else?
3x250W MH will be plenty for this type of tank or you could go with 400W
bulbs in this tank, most people would most likely recommend this
configuration, they do cost a little more (~$20 for the ballast and
depending on the bulb anywhere from $0 to $80 more), they will give a much
higher PAR value (or ppfd) out of your bulbs. Depending on which one you
use, Iwasaki bulbs will give the best PAR. However, some people complain
about the color, they say it's too yellow. Compare the test results with the
10K Ushio's and you'll see the difference (or the light, LOL) in the PAR
values.
Distance from the tank, well lets dispel one myth. Bulbs will not shatter
from being splashed upon by aquarium water. I run my bulbs 3" from the water
line and I have a very turbulent water surface. In the 5 years I've been
running MH, I've never had one shatter or explode on me. I spoke with some
other reefers on this subject and apparently this myth was true with some of
the earlier bulbs, mostly the Venture 5500K bulbs (manufacture defect).
You can keep you bulbs at whatever height you like, 10" up is too high
though IMO. Somewhere in the 4" to 6" range should be good for you. If you
want to keep the glass, so can. It will just be another thing to clean and
if not kept up. It can over time reduce the amount of light getting to your
tank. I would remove it...
Hope this helps, if you need anything more, just reply...
--
Regards,
Mike Raffa
"Zayne Ismail" <sis...@alphalink.com.au> wrote in message
news:3ba4...@news.alphalink.com.au...
> Hi,
>
> I have a 48x14x18 reef and am looking at upgrading my 4 NO tubes to Metal
> Halides. How many metal halides would i need for a tank this size. I was
> thinking 2 250W. Is this enough? is this too much? I plan on keeping some
> high lighting species such as clams and anemones.
>
> Also how high from the water do they have to be. I was planning on putting
> them in my hood so it would be about 8-10 inch from the water level. Is
this
> ok? I have also noticed taht all tanks with MH's dont have cover glasses
on
> them. Why is this? Can i still have my cover glass if i use MH's? Will it
> effect the lighting?
>
> Thanks
>
> Zayne Ismail
> sis...@alphalink.com.au
>
>
>
David Fruehwald
"Zayne Ismail" <sis...@alphalink.com.au> wrote in message
news:3ba4...@news.alphalink.com.au...
> Hi,
>
> I have a 48x14x18 reef and am looking at upgrading my 4 NO tubes to Metal
> Halides. How many metal halides would i need for a tank this size. I was
> thinking 2 250W. Is this enough? is this too much? I plan on keeping some
> high lighting species such as clams and anemones.
With a good reflector, MH lights should cover a 2 ft square area. So two of
them would work well for you application, at least thats what I would use.
> Also how high from the water do they have to be. I was planning on putting
> them in my hood so it would be about 8-10 inch from the water level. Is
this
> ok? I have also noticed taht all tanks with MH's dont have cover glasses
on
> them. Why is this? Can i still have my cover glass if i use MH's? Will it
> effect the lighting?
Height sounds good, you will need to consider fans to vent the hood. You
will have a lot of heat to deal with and if you don't vent it from the hood
it will raise the water temp possibly several degrees. Without fans my 250
watt lights can raise the tank temp 5 degrees, dont ask me how I know : (
I leave my tank open for the evaporative cooling. I would put splash
shields in the hood and leave the tank open, but thats me. You can try the
glass cover but monitor temperture closely. Overheating has been the
biggest problem I've had with my MH lights in the past 2 years since I setup
the tank.
I'm using the Blueline eBallast 250W with the new 10K Blueline bulb and
really like it.
> Thanks
>
> Zayne Ismail
> sis...@alphalink.com.au
>
>
>
>
John&Jana
JerseyReef wrote:
Bull. You've just been lucky. They can and will shatter if splashed. Period.
If you want to mount them close to the water without any splash protection, you
are taking a risk. And cleaning pieces of shattered glass out of a reef is a
real bitch.
IME anyway...
John
JerseyReef
Bull. You've just been lucky. They can and will shatter if splashed.
Period.
If you want to mount them close to the water without any splash protection,
you
are taking a risk.
John,
I believe that is an issue that has been debated time and time again. I just
don't buy into it... If you've had bulbs shatter on you, I'm very sorry to
hear that. I don't believe that mine is just pure luck either, I know plenty
of reefers that go as close as mine with no ill effects to the bulb. In the
5 years I've run MH bulbs I've NEVER had one shatter on me, the risk is nil
IMO.
Happy reefing!!!
--
Regards,
Mike Raffa
"John&Jana" <jdo...@wans.net> wrote in message
news:3BA4C5C0...@wans.net...
westcott
Most of the recommendations are right on.
Lamps will break if splashed on and need protection. Do a search on this
site and you will find at least two or three reports of this very thing.
One last issue that no one touched on is Ultraviolet Radiation. All
lamps should be shielded. The outer glass tube on most lamps has been
shown to be ineffective.
If you want to read more, visit my site under hardware\lighting. You
will find several relevant articles that will help you and Dana Riddles
article on UV. UV does not induce color as often touted. It is
detrimental to coral growth in most cases, not to mention human eyes.
westcott
http://www.farmfrags.com
R. S. Pearce, Jr.
out two 12KK Sunbursts with one "spit", I have 3x250w about 4" from the
water.
--
Bob Pearce
"JerseyReef" wrote ...
>snip<
CJ Oster
incandescent bulb and put in in a lamp socket. Turn it on and let it get
good and hot. Then squirt it with your little brothers water gun. Wait
about 4 seconds and stand back. MH's get much hotter than incandescent
bulbs. The issue isn't the water, it's the change in the temperature. If
you keep you halides cool enough (with enough water splashing on them ;-) or
fans or something) you won't have the problem, but if you take a piece of
glass the size of a dime and drop the temperature to 100C almost
instantaneously, it will shatter because of the contraction caused by the
cooling...unless the rest of the bulb is only slightly warmer.
-CJO-
"JerseyReef" <jerse...@home.com> wrote in message
news:Jp4p7.19485$5A3.5...@news1.rdc2.pa.home.com...
Simon O'Keeffe
the water with the same/more light as the 250s. Saves the problem of splashing
them.
Put em like 18-20" above the water and get the 400s. Bit of a waste of watts
though.
Simon
John Hudson
> Also, how often do i have to change the bulbs on MH's? Is is the same as
NO
> tubes (6 months approx)?
JerseyReef
Iwasaki bulbs generally last 12-16 months
20K Orsam last 6-8 months
10K Ushio 10-12 months
Mileage can vary depending upon ballast used, etc...
--
Regards,
Mike Raffa
Jerse...@home.com
"John Hudson" <grey...@onebox.com> wrote in message
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