My aquarium water tests out as very hard. I use well water that is in an area known for lime content. I add water to the tank that has been run through a Brita filter. Can I use aquarium salt to soften the water?

Aquarium salts also hardens water by raising the alkalinity levels.
If you have a freshwater aquarium, it would be best not to use the freshwater aquarium salt as it will not soften the water.
Happy Fishkeeping:)