Fan positions

What's the best way to position a fan:
1. Placing it on top of tank so that it blows directly on the water surface (vertical)
2. Placing at the sides so that it blows across the surface (horizontal)

 

I would place it off to the side, so if it falls, it does not land in the tank! ;D
I think that way it would also go over more surface area
Just an opinion!

 

Across the surface Bob

 

lol if anyone says place on top im gona laugh...my you'd be having fish stew if it fell...

 

Definately pointing across the water surface. I have one in my canopy pointing in across and one on the other side directly across from it pulling air out kinda like a wind tunnel.

 

If it falls you should kick yourself for bieng a bad DIY'ist.....I avoid the problem and keep an open back canopy with 2 large fans drawing air outta the canopy that blow across the open back section creating a vacum as you would if you had a sealed canopy for the best airflow, also puts less stress on the fans. If your fan has a lip on the top and you face it the right direction, physics (the person ;D not the system by which all movement on earth is governed) tells me it is impossible for the fan to fall in....and unlikely even without a lip if you mount it properly. Never heard of that, but then again if i did somthing that depressing i porabably woulnt tell anyone either. I would take the back off if you have one and do as most others have and blow acroos not up....closed back canopies are too hot for my liking (gets about 104 in the sumer here). Blow across and open the back, thats solved most heat issues ive run into.

 

[quote author=shawnz28 link=board=General;num=1105072636;start=0#4 date=01/09/05 at 20:22:13]Definately pointing across the water surface. I have one in my canopy pointing in across and one on the other side directly across from it pulling air out kinda like a wind tunnel.[/quote]
Nicley put, also creates more air water contact...more cooling.

 

My assumption (apparently WRONG!) was that this was a fan blowing across the sump....hehe.... ;D

Thus the falling in comment....hehe....and I am a poor DIYer and have stuff fall all the time!!! LOL! :

 

Ahhhh! thats scary, im total OCD on things staying in place. I was probably dropped alot as a child and somehow try to makeup for it... ;D

 

everyone,
thanks for the comment and info, surely appreciated. i do have currently 1 fan (4&quot blowing across the surface though i've seen others blowing it on top of the water. just wanted to be sure.
that vacuum thingy is an interesting option that i could try if i put on my tank cover later on. i'm having an open top for the moment.
thanks again, guys (n gals)