I've had several fish deaths over the past 6 months. I'm noticing a lot more Iron in my water and it seems like I lose fish after a water change. I had the water tested and it's got very little hardness in it but plenty of Iron. The culligan man said I could install a water softener and then do reverse osmosis for cooking, drinking and using in my fish tanks. I have no clue what any of that means. Does anybody have and suggestions of tips if you use this particular process?