Hard Water Plants
Good morning Stan...
I don't worry about the hardness and pH in my tank water. They aren't that important. Plants prefer more acidic water, but will adapt to your water conditions. Lighting is a lot more important.
If you have 1 to 2 watts of light per gallon of tank size, and regularly add fertilizer, then you can grow most aquatic plants.
I use pea gravel substrate and plant my plants in pots with some organic potting mixture, but there are many other gravel types on the market. Do a little research online or ask this specific question on this forum.
"Fear not my child, just change the tank water."