Chiller and Fan

[Aquattro]

nope, no use for a fan at all. There are no hot spots from lights on the water, since it's moving. The fans were never intended to cool the bulbs, so stop thinking that.
I still get plenty of evaporation for kalk top off, and I don't have the noise of a fan.
For me, one of the biggest benefits of adding the chiller was getting rid of the fan.