No, stay away from that.
You will need to add a by pass valve for the softener. This line will be where the softener is installed and then run the water line(Hot and cold) to the tank or a spigit where you can attach a hose for refilling the aquarium.

You never want to water house plants, gardens etc with softener water.
So you should add a by pass!!

It'll cost a bit, but it'll make life much better.
Also, use KCL, not NaCl, it cost more, but is better for you(K+ vs Na+) for various cooking and other things.
Some use that in their softeners but it still causes issues because the amount of KCL is so high relative to what we add for nutrients.


Regards,
Tom Barr