how far above tank for lights?

Just got my new 40 gallon tank and stand set up. Have the AH supply 96 watt
lights and after putting the lights in the hood found that it was raising
the temp of the water due to the glass top getting too warm. I reworked the
hood and now have the lights setting on top of the hood, about 8" from the
glass top. Much better, but am I losing any effectivness of the lights at
this distance? Thanks.
--
Paul

"Paul" wrote in message
...
Just got my new 40 gallon tank and stand set up. Have the AH supply 96
watt
lights and after putting the lights in the hood found that it was raising
the temp of the water due to the glass top getting too warm. I reworked
the
hood and now have the lights setting on top of the hood, about 8" from the
glass top. Much better, but am I losing any effectivness of the lights at
this distance? Thanks.
--
Paul




You're better of installing a fan to cool the lights. Cooler bulbs run more
efficient, also by raising the lights you wasting a lot of light.

Harry




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"Harry Muscle" wrote in message
...
"Paul" wrote in message
...
Just got my new 40 gallon tank and stand set up. Have the AH supply 96
watt
lights and after putting the lights in the hood found that it was
raising
the temp of the water due to the glass top getting too warm..
--
Paul




You're better of installing a fan to cool the lights. Cooler bulbs run
more
efficient, also by raising the lights you wasting a lot of light.

Harry

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Hey, thanks for the reply.
I have two 25 watt computer fans blowing across the bottom of the fixture
and at the 8" the glass top is cool to the touch and tank temp has not being
affected the last 24 hrs. However I will expeirment and try modifying the
hood to lower it a little at a time to see just how much lower I can get it
without affecting the tank temp. I need to re design the hood anyway.
--
Paul

i have a hood with 192 watts, it comes with a fan so the lights would not
affect the temperature. if you have two fans i would recommend lowering the
lights until just above the tank. also, you loose many watts with pedant
lights.

take care.

"Paul" wrote in message
...

"Harry Muscle" wrote in message
...
"Paul" wrote in message
...
Just got my new 40 gallon tank and stand set up. Have the AH supply 96
watt
lights and after putting the lights in the hood found that it was
raising
the temp of the water due to the glass top getting too warm..
--
Paul




You're better of installing a fan to cool the lights. Cooler bulbs run
more
efficient, also by raising the lights you wasting a lot of light.

Harry

-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
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-----== Over 100,000 Newsgroups - 19 Different Servers! =-----
Hey, thanks for the reply.
I have two 25 watt computer fans blowing across the bottom of the fixture
and at the 8" the glass top is cool to the touch and tank temp has not
being
affected the last 24 hrs. However I will expeirment and try modifying the
hood to lower it a little at a time to see just how much lower I can get
it
without affecting the tank temp. I need to re design the hood anyway.
--
Paul

"Carlos" wrote in message
...
i have a hood with 192 watts, it comes with a fan so the lights would not
affect the temperature. if you have two fans i would recommend lowering
the
lights until just above the tank. also, you loose many watts with pedant
lights.

take care.

The light is setting on top of the 8" hood at the moment. At the bottom of
the fixture it is enclosed and the only light escaping would be out the back
of the partially open back of the hood. Thanks.
--
Paul

"Paul" wrote in message
...

"Carlos" wrote in message
...
i have a hood with 192 watts, it comes with a fan so the lights would
not
affect the temperature. if you have two fans i would recommend lowering
the
lights until just above the tank. also, you loose many watts with
pedant
lights.

take care.

The light is setting on top of the 8" hood at the moment. At the bottom
of
the fixture it is enclosed and the only light escaping would be out the
back
of the partially open back of the hood. Thanks.
--
Paul




The problem isn't always with light escaping the hood when it's far above
the tank. A lot of light is lost because of the angle that it hits the
water, it simply reflects off the surface and get's bounced around in the
hood until it either escapes or gets absorbed. When you raise the height of
light source the ang ecome less favourable for entering the water. So
even if you've got a perfectl losed hood, it's still best to have the
bulbs as close to the water as possible, unless of course your hood is
covered with mirrors inside.

Harry




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The problem isn't always with light escaping the hood when it's far above
the tank. A lot of light is lost because of the angle that it hits the
water, it simply reflects off the surface and get's bounced around in the
hood until it either escapes or gets absorbed. When you raise the height
of
light source the ang ecome less favourable for entering the water. So
even if you've got a perfectl losed hood, it's still best to have the
bulbs as close to the water as possible, unless of course your hood is
covered with mirrors inside.

Harry



Thanks for the help folks, appreciate it.
--
Paul

"Paul" wrote in message ...
The problem isn't always with light escaping the hood when it's far above
the tank. A lot of light is lost because of the angle that it hits the
water, it simply reflects off the surface and get's bounced around in the
hood until it either escapes or gets absorbed. When you raise the height
of
light source the ang ecome less favourable for entering the water. So
even if you've got a perfectl losed hood, it's still best to have the
bulbs as close to the water as possible, unless of course your hood is
covered with mirrors inside.

Harry



Thanks for the help folks, appreciate it.


I had no idea how much light temperature could affect water
temperature. I have a 60gal tank which is almost 3ft deep and my 3x25w
tubes are doing a great job of keeping the temp around 24c and that's
with a temp sensor near the bottom of the tank. I'm restricted by the
tank length so couldn't go for higher watt tubes but I'll stick with
my restricted choice of low light plants and the trade off is I don't
need the heater (which I bought brand new....doh).