agree that it's fine, but if you are concerned, which you don't need to be, you can either get a small fan to cool the water when the lights are on, or raise the heater temp up a degree or two. If it where me and I was doing something I'd raise the heater temp. This way there is nothing new to buy, a fan will increase the evaporation, which will mess with the salinity, and could cool it below the current heater temp, causing it to heat more and the two will fight each other.