Auto Water Changer - Heating Question

I'm planning on incorporating an automatic water changer into my 300 gallon system (figuring on ~350 gallons including wet/dry/sump/etc).

Since the ambient room temp here in AZ tends to be around 78F or so, I don't need nearly as high wattage heater as I used back when I lived in SD and the ambient room temp was around 68F. However, I will be dripping in ~3GPH of cooler water via my water changing system and was wondering how to best go about adjusting my heating needs for this new water. Granted, it's less than 1% of the total tank volume being added per hour, so it won't impact the tank's temp too much, but I'm sure I need to compensate for this some.

What would you guys recommend as far as a heating solution for me if I wanted to stay steady at the good ole standby of 78F? What if you were doing Discus in this tank (tank temp of ~84F)?

Thanks!

So essentially you're saying that you don't have to compensate for the drip system at all and to just think about my heating needs as if it didn't exist. Definately good to know since that'll save me a bit of cash. Cool!