Because the city water here is so hot in summer cold 90F I have been trying to find ways to minimize the temp increase and at the same time increase O2 levels which drop about 3 PPM as most tap water softened or not is low in O2. For today's water change it suddenly occurred to me that if I could create a fountain like they do on ponds and man made lakes to cool and oxygenate water it might work for my aquarium as well. So today instead of the usual python hose pouring in water, I attached a garden sprayer and locked it in the wide spray pattern position. The end result was instead of the usual 7F degree increase in temp, the increase was only 3 degrees. Also O2 levels only dropped by 1 PPM instead of the usual 3 PPM. Anyway for those that live in the high desert here is something to consider.