Splenda [...] Perhaps you could do part Splenda and part sugar?

Splenda is Sucralose. Sucralose is the sweetening chemical in the water enhancers. I am already doing what you're telling me to do. Most people don't add the sugar.

I do because I don't like the afterbite of Sucralose. It spoils the flavor.

Aspartame is far worse to the point I wont even touch it, and sugar does not get rid of the aspartame bite.

The amount of sugar I'm using per pitcher is about 5~6cents.

The most expensive component is the sucralose water enhancer.

Wikipage for the curious

https://en.wikipedia.org/wiki/Sucralose

Common brand names of sucralose-based sweeteners are Splenda, [...] Sucralose mixed with maltodextrin or dextrose (both made from corn) as bulking agents is sold internationally by McNeil Nutritionals under the Splenda brand name.