I just googled the Columbus (LewisCenter) Ohio water quality report.
Average pH is 7.8, with 7+ grains of hardness (medium hard).
This is not the kind of water I would consider to be healthy for wild tetras of the Amazon region. They would appreciate a pH of 5 with almost no hardness.
And although Panda uaru were one of my most desired fish, I had water similar to yours, and it would be a losing battle to try nd keep them.
The kind of water parameters you have would be extremely stressful for the fish you ordered.
And by adding salt, you are making the water even more osmotically inhospitable.
If it were me I'd stick to locally raised tetras, or fish that are comfortable in your water conditions.
From looking at the constituents of your local water, ou have the kind of water that works for Central American, rift lake African, or the South American species from west of the Andes, not for soft water Amazonian species.