Fans to cool tank


Reefing newb
Well summer is coming and the tank stating to get warmer.

I'm, thinking about using 120mm Computer Case Fans to cool the tank..

That brings me to my question. I have a 56 gallon column, and my friend has a 120 gallon tank as well as a 75 gallon tank.

Anyone ever cooled there tank with PC fans? If so how many fans did it take to get the job done. I'e only ran test in a bucket to see if it would drop the temp and it did, I'm just wondering if anyone done it over a larger surface area..

Since it not warm to try it on the tanks, looming for advice.
Start with 1, maybe 2 for the 120 and go from there. There are controllers to run heaters and fans based on tank temp, too.
I use a twelve inch on a 24g and freeze RO/DI into blocks and put them in my ATO. And my ATO fills the tank very slowly. With an ambient air temp of 90 I can keep the tank at 81. But keep in mind that the fan will cool much better without any humidity in the air.
I also noticed that with more surface area with the hob filter on the back with an open top along with more surface agitation will help with the fans cooling efficiency