Before we installed our water softener unit, we bought one of those home test kits. We bought our unit from a mail order company where you compare your results with a chart on their web page to choose the correct sized unit for your needs. Believe it or not, it came by UPS the next afternoon, and we promptly installed it.
This cleared up our water (our well water was previously yellow), and has taken care of the staining issues in the toilets, etc., but it still has a "rotten eggs" smell when you run the water. After you pour it into the glass, it's not noticable any longer, but only while it's first running from the faucet.
What causes this, and how can it be fixed? I very happy with this unit that I bought by mail order and it seems it works just fine and is sized correctly for our needs, and I'm hestitant to call a commisioned salesperson to the house to sell me something I don't need. I'm very confident that someone can give me a solution to something that seems pretty simple to fix...