This summer I got tired of keeping the whole house ac on, it only got my tank down to about 80, and a noisy fan barely got it to 79, plus I had to work double time to get my ato full. Since a chiller for my 150 gallon system would cost in the neighbor hood of $700, I went and bought an ac window unit. It ran me $99 and took 10 minutes to install. I put it on my Apex with the knobs turned to the highest setting. Whenever the temp goes above 79.5 degrees, it cools the whole room and brings it down in minutes. The room never gets hot enough to heat the tank above 80, and the unit barely has to run, so long as the door is closed. The temp has been rock solid stable for the past couple days, never below 79.3, never above 79.6. I will post pics of the unit, I believe it is a 2500 BTU