Better late than never! Small fan on the surface and that will overcome the heat from the pumps plus some. Bacteria growing on bio balls needs to be wet aLL of the time and have circulation preferably suspended in the air because bacteria Love's oxygen. Ammonia eating bacteria takes three to six weeks to build up so you do not want to let them dry out and die. Temperatures below 55 degrees will kill them too. They prefer 80 degrees.
I have 25 gallons of bio media over a 400-gallon system. When they do not have ammonia to consume because the bait is all pooped out or gone I feed them ammonia daily so that they will be populated and ready for the next load. They starve out easily. They do not carry a few weeks of reserves around like we do :-) I got tired of buying clear ammonia so I resorted to the easier method by peeing in it :-) Daily! And testing to make sure the level comes back to ZERO in a day.
After testing twenty or thirty times you will have a good idea of what to expect it and will not have to text anymore unless something happens like a power outage
This is the best way to oxygenate the water and keep it clean
Google bio filter cycling