UV shielding glass or not?

[Mislav]

Hi

I'm planing to build custom lighting for my new aquarium. I'm going to put 2
* 250W doubleended MH bulbs. Is it necessary to put UV shielding/filtering
glass between bulb and surface of aquarium? If it is necessary, would 4mm
thick plain glass be good?

Thanks

Mislav

[BiG_Orange]

> I'm planing to build custom lighting for my new aquarium. I'm going to put
2
> * 250W doubleended MH bulbs. Is it necessary to put UV shielding/filtering
> glass between bulb and surface of aquarium? If it is necessary, would 4mm
> thick plain glass be good?

UV 100 percent required.

[Pszemol]

"BiG_Orange" <@> wrote in message ...
> > I'm planing to build custom lighting for my new aquarium. I'm going to put
> 2
> > * 250W doubleended MH bulbs. Is it necessary to put UV shielding/filtering
> > glass between bulb and surface of aquarium? If it is necessary, would 4mm
> > thick plain glass be good?
>
> UV 100 percent required.

UV is required or UV shielding is required? :-)

[Patrick]

Yes, with double-ended bulbs you will need UV shielding, since they
have no integrated shielding like mogul-socket bulbs.

Plain glass doesn't have much in the way of UV blocking.



"Mislav" > wrote in message >...
> Hi
>
> I'm planing to build custom lighting for my new aquarium. I'm going to put 2
> * 250W doubleended MH bulbs. Is it necessary to put UV shielding/filtering
> glass between bulb and surface of aquarium? If it is necessary, would 4mm
> thick plain glass be good?
>
> Thanks
>
> Mislav

[Anthony]

Believe it or not, most plain glass is actually a good UV blocker. Most
reptiles need UV bulbs for good health and it's a requirement that there is
no glass or plastic between the light and the animal because too much UV is
blocked. Think of it this way...you can't get a suntan sitting in front of a
sunny window, because the glass blocks the Uv required to tan


"Mislav" > wrote in message
...
> Hi
>
> I'm planing to build custom lighting for my new aquarium. I'm going to put
2
> * 250W doubleended MH bulbs. Is it necessary to put UV shielding/filtering
> glass between bulb and surface of aquarium? If it is necessary, would 4mm
> thick plain glass be good?
>
> Thanks
>
> Mislav
>
>

[BiG_Orange]

> Believe it or not, most plain glass is actually a good UV blocker. Most

You are 100 percent wrong, normal glass like at lowes has about 3 percent UV
filtering.

[Anthony]

Ok, this is from a window building site..
http://www.glass-rite.com/seventhings.html
It states that the UV tranmission of clear 1/8" glass is 73%. Most corals
are adapted to living near the surface, under full direct sunlight (which
has a much higher UV rate than a metal halide light at an average of 6 to 12
inces off the water) stick your hand under the metal halide for an hour and
do the same outside on a sunny day at noon and you'll see what I mean. A
blocking rate of 23%, especially considering that the UV output of a halide
DRASTICALLY drops off after a one to two hundred hour burn in period, is
usually more than adequate. Any halide under idea conditions should have a
minimum 100 hour burn in period somewhere other than over your tank.



"BiG_Orange" <@> wrote in message ...
> > Believe it or not, most plain glass is actually a good UV blocker. Most
>
> You are 100 percent wrong, normal glass like at lowes has about 3 percent
UV
> filtering.
>
>

[Anthony]

Excuse me, I wasn't paying attention when I was typing......plain glass
blocks 27% of the uv, not 23%

[BiG_Orange]

"Anthony" > wrote in message
. ..
> Excuse me, I wasn't paying attention when I was typing......plain glass
> blocks 27% of the uv, not 23%

Bottom line, you need to use UV filtering on your body, your sunglasses etc.
Why that doesn't make sense to you, I'm not sure.

Read this:

http://www.nano-reef.com/forums/showthread.php?s=&threadid=25782

[Anthony Pruitt]

Yo dude, I never said don't filter, we just have a different opinion on what
is adequate. Bottom line, a large percentage of animal life require some UV
for survival. Vitamin D (sometimes known as the sunshine vitamin) is one of
the few that can be produced inside the body. UV radiation striking the skin
stimulates it to produce the vitamin D. Now guess what the main function of
vitamin D is in most animals....it aids in the absorption of calcium. Some
UV even adds to the color development of alot of corals. You are 100 %
correct in stating that too much UV can be harmful, we just have different
opinions on how much exposure that takes. I personally run all my tanks open
top with nothing between the light and water at all and I have had no
problems. But reefs are like everything else, there are 100 ways to do it
and it still be right, so whatever works for you is cool, stick with it.





Bottom line, you need to use UV filtering on your body, your sunglasses
etc.
Why that doesn't make sense to you, I'm not sure.

[Benjamin]

Wow! guess that is one reason why my tank likes a little bit of natural
lighting on a regular basis. :-)

--
--

My Web Site: http://showcase.netins.net/web/reefpage/



"Anthony Pruitt" > wrote in message
. ..
> Yo dude, I never said don't filter, we just have a different opinion on
what
> is adequate. Bottom line, a large percentage of animal life require some
UV
> for survival. Vitamin D (sometimes known as the sunshine vitamin) is one
of
> the few that can be produced inside the body. UV radiation striking the
skin
> stimulates it to produce the vitamin D. Now guess what the main function
of
> vitamin D is in most animals....it aids in the absorption of calcium. Some
> UV even adds to the color development of alot of corals. You are 100 %
> correct in stating that too much UV can be harmful, we just have different
> opinions on how much exposure that takes. I personally run all my tanks
open
> top with nothing between the light and water at all and I have had no
> problems. But reefs are like everything else, there are 100 ways to do it
> and it still be right, so whatever works for you is cool, stick with it.
>
>
>
>
>
> Bottom line, you need to use UV filtering on your body, your sunglasses
> etc.
> Why that doesn't make sense to you, I'm not sure.
>
>

[Richard Reynolds]

> opinions on how much exposure that takes. I personally run all my tanks open
> top with nothing between the light and water at all


what kind of lights do you have over your tank???

--
Richard Reynolds

[Anthony Pruitt]

My 75 has two 250 watt metal halide german 10K mogul bulbs(I don't remember
the exact brand without digging out the boxes), and 4 65watt Corallife PC
actinics...all mounted in the hood about 12 inches off the water, with a
full reflector, with two 120mm, 3000 rpm fans to help with cooling

The 46 bowfront has an Aqua StarLight Fixture with 2 x 150W 10,000K HQI
Double Ended bulbs, and a single 65 watt Corallife PC actinic


"Richard Reynolds" > wrote in message
news:hhRZb.6652$rd2.1034@lakeread05...
> > opinions on how much exposure that takes. I personally run all my tanks
open
> > top with nothing between the light and water at all
>
>
> what kind of lights do you have over your tank???
>
> --
> Richard Reynolds
>
>
>
>
>

[Pszemol]

"Anthony Pruitt" > wrote in message . ..
> I personally run all my tanks open top with nothing between
> the light and water at all and I have had no problems.

Could you please give some details about your setups?
- What lamps & bulbs do you use and for how long?
- How far away from the water surface?
- How deep in the water do you keep animals?
- What kind of animals inhabit your tank? (from top to bottom)

I would appreciate that info from a person not using UV
shielding and experience no problems with burning/bleaching.
I am in the process of researching DIY fixtures, it will help :-)

[Anthony]

I have rock in both tanks basically from the bottom all the way to an inch
or two below the surface, with corals all the way up. Both tanks are a mix
of soft corals and a few LPS corals. Circulation is from a various mix of
powerheads positioned around the tank to eliminate dead spots and provide
current. One thing I did that really seemed to help is install a spraybar at
the bottom, behind the rock. It keeps the detritus from settling and allows
the filters to pick it up. The power compacts are set to come on about an
hour before the halides, which are set to a 10 hour period, and go off an
hour after the halides. The halides are mounted about 12 inches off the
water's surface. Running them with no shielding can be dangerous if you
aren't careful. Sometimes all it takes is a slash of water on the extremely
hot bulb and they can literally explode. Plus the bulbs have to cleaned
occasionally because no matter what you do, some salt will build up on them
greatly cutting down the output. The type of lighting I have is in a
previous post in this thread.

As far as the animals.....there is a mix of dozens, with the LPs corals near
the bottom in the dimmer light and out of direct current. Most of them will
survive higher in the tank, but they tend to open wider in the lower light.
They expand their surface area for light absorption to make up for the lower
light levels. And I keep them out of strong direct current because it tends
to rip them from the skeleton if they open too wide. For the most part,
leathers, gorgonians, anthelia, xenia, and various zooanthids are fairly
bulletproof and can survive anywhere in the tank.

If you notice the posts and various articles on bleaching and burning, you
will see a pattern....it's usually the sps corals and it's soon after they
add, or change bulbs, or add a new coral. New halide bulbs produce alot of
UV and if they don't get a burn in period or shielding, that goes straight
in the tank.

Also...three reasons corals bleach under certain lights...one is that the
symbiotic algae in each coral has adapted for the water conditions and light
levels of where they are living. Being moved under new lighting or a new
tank sometimes can stress and kill the zooxanthellae present in the coral
since the conditions are different. That's why it's always smart to start
the corals at the lower parts of the tank and gradually move them up to the
required level, giving them time to adjust. Also most corals have the
ability to *switch* and start using a form that will survive in the current
conditions if they survive the bleaching.. Changing out their zooxanthellae
for another strain is why alot of corals tend to change colors when moved to
a new tank.

Second....corals also use pigment to help block Uv radiation just like other
animals. That's why we tan and why most african Americans don't tend to
sunburn. Under the bright lights, most corals tend to get brighter and more
colorful. When moved suddenly under brighter lights or high Uv lights, they
don't have time to adjust and add the required pigment, so they tend once
again to bleach or burn.

Third.....halides produce alot of heat, and that's one of the major causes
of bleaching and burning.

I didn't mean to sound like I was sending you to school, but I was trying to
explain.....most soft corals aren't that picky and can survive alot more
disruption in their enviroment, but if you are planning an SPS tank with no
shielding, be careful, they have alot more problems with it.


..
>
> Could you please give some details about your setups?
> - What lamps & bulbs do you use and for how long?
> - How far away from the water surface?
> - How deep in the water do you keep animals?
> - What kind of animals inhabit your tank? (from top to bottom)
>
> I would appreciate that info from a person not using UV
> shielding and experience no problems with burning/bleaching.
> I am in the process of researching DIY fixtures, it will help :-)