Water Filtration for the Lower Mainland

[Aquattro]

I use an RO that I got for $250. Best purchase (next to the shop vac) I've made for my tank. Not sure why you think it's overkill. I think it's much more economial than using TWP over the long run. Is what you're doing bad? Who knows? Do you have algae problems? Do you see an issue with the water?
Where do you get your water from? How far does it travel in the system? Is the system broken anywhere allowing contaminants in? Will it be broken tomorrow? Does the chlorine level maintain itself for the duration of the travel to your home? If not, is GAC going to remove biological growth?
Basically, if you're happy with your tap water and trust the distribution system, you may be OK. For $250, I know my water is just plain old water. Think of it as insurance.