Temp fluctuations?

Ok i have two tanks with 150 watt MH on them. I live in a small one bedroom apt. The temp outside this time of year is reaching into the upper 90's by 5pm My apt is in the basement so it stays about 75 degrees while the lights and ballasts arent on But when they come on, my place starts the cook!
So i got a small window unit air conditioner, and it keeps my place in the lower to mid 70's while the lights are on. I also got some small fans to use. The problem i am having is that the fans seem to be doing to good of a job cooling the tanks. It seems as maybe i should use either the a/c or the fans but not both I have the fans on the edge of the tanks. At first i was blowing them directly at the waters surface. This was cooling the tanks off way to fast, like a few degrees an hour So i started aiming them up a little bit every day till i get them in a position to keep the temps pretty consistent. It is very tricky and time consuming.
And also i have been running underwater lights in the back chambers of the tanks to grow some cheato. These lights come on when the daylights go out and by the end of the refugium light cycle the tanks are at about 80degrees. I do not run the fans while the MH are off.
I am starting to have paranoid thoughts that in an effort to keep temperatures consistent, i am actually making them fluctuate more. Before i tried to get my temps down i was going from about 75, 76 to 80, 81 over a 7 hour period. Now with the fans, a/c and refugium light, sometimes i check the tank temps and have to reposition the fans or turn off the a/c because the tanks are too cold. When i first started the fans i was repositioning them a handful of times a day to get the right spot.
Were these actions even worse than a few to many degrees fluctuation?
I feel that the original change in temp was at least consistent everyday and not bouncing around every hour
I am confused and need some assistance please
Sorry about the Novel.................

 

I keep my heater set at 78. Tank only fluctuates between 78-79. It has reached 80 once or twice when it was 100+ outside. When I originally set up the tank I had the heater at 76. It fluctuated between 76-79. Setting the heater a couple of degrees warmer seemed to help me. Might not work for you though, but I'd find some way other than what you are doing as there is no way I'd suffer with the AC off just to keep the tank warmer.

 

Honestly that sounds like way too much work. You really need a controller to set your lights, heaters and fans on. They will all work together on a controller.

The controller will turn your heaters on at lets say 78.4, they will turn the fans on at lets say 80.1, it will also turn your lights on and off when ever you program it to and even shut the MH lights if the temp gets to 81 if you want.

Really the way to go!!!!

 

hmm... I think, long term, it's worth the effort to get this right. Short term, you may be right about it bouncing around a bit too much.

I also agree a controller is your best option, but that may be out of your price range.

In which case I would suggest just using one fan per tank (can't tell if that is what you're doing or not) and I might get one of those cheap analog timers from Walgreens/CVS and set the fan to come on like for 15 minutes once an hour while the lights are on or something like that.

 

thanks yall. i will try to get a cheap analog timer for the fans. this wont be an issue as soon as the heat subsides.

 

my reef gets up to 87 degrees with the MH on! but the lowest it will go is 82. You shouldn't have any problems because I have not seen any problems in my fish/corals/inverts and my temps are WAY up there!

 

Wow....87 is high....maybe you should get a cheap fan for when the MH's are on too!!!

 

The last week or so its been triple digit weather so toda Im gonna start putting this frozen 2-liter in the sump every afternoon