For a tankless water heater and whole house boiler there is a neutralizer installed in my boiler room. It has not been refilled in more than a year.
After some research I found out that I should use either limestone gravel or marble chips to refill the neutralizer housing. Sometimes pelleted limestone seems to be added additionally.
So my plan is to get "Marble Chips" from a home improvement store for a few dollars. I'll refill the neutralizer and measure the pH after a few days. If it's not neutral, then I'll add limestone pellets (like "Garden Lime"). Am I going right about this?