Actually just Na would be bad
It'll burn in water!
But luckily it's not just Na, it would be Sodium bicarbonate.
Yeah, that's why I backed out of my searches and originally didn't say anything. I knew I was over my head on the subject.
However, I did see enough that suggested merely having a water softener wasn't the end of the story. Some people have found ways to make it work quite well. And given the OP's location is Wisconsin (cold!), I thought it might be worth a little extra checking so he can have hot water when winter comes.
[No issue at all in pulling the torch out. Maybe $20-30 in materials (copper T and valve) and an hour of my time.] Would still likely need to get some 5-10 gallon jugs and let it is sit for a day or two to get the temperature up to ambient. But it would be MUCH easier getting it straight from the tap considering easy of temperature control.
Here's a number of other threads on this board from people using water softeners with planted tanks. Some offer ideas that may be useful. Even though the torch may not be a problem, there may be an even better way to go about it. It's certainly worth checking out while still in the planning stages. Then, if you go ahead with the torch idea, at least you'll know you made an informed decision.