Heat

[GaryP]

It depends on their cfm. I had 4 old 30 cfm fans on my 125. I replaced them with new 100 cfm fans and now I only run 2 of them on a timer when the lights are on. I was running all four before and still not keeping up.

Try starting with 2. You can always add more later.

Gary

[Polkster13]

Also, keep in mind that the air movement over the water surface is going to cause lots of evaporation (which has a cooling effect on the water). You will need to keep a mindful eye on your water level, especially after you add the fans, to see how much water you are losing and replace it with RO water.

[DeletedAccount]

Also the Target or Wal-Mart clip on fans will work great until you find the perfect answer and look around. They run less than $5. I would get on for the canopy and one for the sump, personally. This is what I use on the 180.

[Reef69]

those ebay ones Monica said look cool..but if i put any fans no a timer with the MHs, it should be ok..right?

[::pete::]

I use a 3-way in the timer and plug in my MH's and fan's when the halides kick on (off) so do the fans. Have the fans pointing in from both ends not out this way it will blow cooler air across the water and not shorten the life of the fan that would be sucking the air (salt) out.

[Reef69]

yeah, makes alot of sense..well, Im going to school right now but will go to radio shack and target, hopefully those fans work. Thanks everybody

[Reef69]

alright, i just installed an 85 CFM cooling fan i bought from radio shack, its pretty small and works great, I just bought 1 to test it and my water doesnt go over 81..im guessing it will cool down once i install the other one..it has a 10,000 continuous hour life, which its good..anyways, will keep you posted..