Re: cooling down your water

[Eric McGlohon <eric at dekard_com>]

On Tue, May 14, 2002 at 01:43:42PM -0700, Joe Reiter - Bigfoot wrote:
> Get a small fan and blow it directly across the top of the water.  That
> rapid airflow right across the waters surface will significantly increase
> the evaporation of the water, which will drop the temperature.  The downside
> is that you'll have to top off the water in the tank more often, since you
> are increasing the evaporation so much.  A friend of mine was mentioning
> this to me.  (Don't know if he still reads this list.)  He said that on his
> girlfriend's tank (30 gallons or so?), he took a simple CPU fan from a
> computer and mounted it so that it was blowing across the water surface.  He
> said it really made a big difference.

I'd just like to chime in here - Joe is absolutely correct.
Evaporative cooling is very effective.  I have a reef tank, and
there temperature is much more of a concern, the lights generally
much more intense and therefore hot.  If the temp fluctuates by
more than 5-7 degrees F above normal corals can bleach and die.
I have 2 4" computer fans in my hood, and when they are on they
can keep the tank temperatures 2-4 degrees cooler than the ambient
room temperature.  More fans, more cooling.  If you have a sump
you could put a really big fan on the water in there.

You will have to top off for loss due to evap (I loose about 1
gallon/day), but you can automate that with a pump and a float
switch, especially if you have room underneath your tank to store
the equipment.  Also it can be useful for dosing fertilizers and
such.

Good luck,
-Eric