very hard water

Question
HI Ron, Hope you can help me no one else can give me a straight answer and maybe there isn't one. I would like to know if I can use my well water for a fresh water fish tank. The water is very very hard, I've had the water tested with three different water authorities and given three different answers all the way from 75 grains hard to 120 grains hard. My water also has iron, mild sulfur, Ph and alkalinity are sky high off any aquarium water test kit. I have a water softener system in my home but the local pet store owners say that I cant use that water because it replaces calcium and magnesium with sodium. Now the dealer I purchased the softener from claims that the media in the softener traps the minerals that cause hard water and the salt is used only to rinse and regenerate the spent media and is sent down the drain with no salt ever reaching the faucet. I purchase a tap water filter from a local pet store that promised pure water from 25 gallons to 125 gallons depending on your water quality, this unit had a gold media in it that turned purple when it was expired. I got less than six gallons before it turned purple and a full refund. From what have gathered from books, Internet, people, and others, water consistency is more important that quality. That makes sense to me but there must be a limit. My water is safe for human consumption (according to water authorities) no ammonia, bacteria, nitrites, or nitrates but is it safe for fish. Some of the pets stores I have talked to say that I absolutely can not use my water ether raw or softened(unless It was run through an R/O unit, which I will not use because of the high waste water), and others said its fine I would just get a little more algae. I know my water is good for salt water tanks because I have had great success with marine tanks, but I am somewhat going backwards and would like to try freshwater for a change. The tank I'm planing on using is 110 gallon. I have tons of filters and equipment and pretty much understand that aspect of the hobby just confused with water conditions. I'm thinking of keeping a single or maybe pair of Oscars mainly because of there hardiness and of courses personality. I know they would survive even in very poor water, but I don't want them to just survive, they need to thrive and be comfortable and happy.  I don't want to set up a tank and toss in an Oscar and see how it goes, I want to know that this fish will have the water that it needs. Maybe my water is fine for Oscars and other cichlids but no really seems to know or care as long as I buy my fish and mostly useless water conditioners from them. With all that being said I thank you for your time and look forward to hearing any helpful info you may have.

Answer
Hi Brian,
  Your water is likely okay, it is just a matter of which fish it is okay for.  For example, I have done work in Nicaragua, in some of the lakes there, where the water is so hard and alkalilne that you have to rinse off your dive gear right after or it gets coated in lime!   

  Oscars would not likely do well in your water.  They want something more neutral or even slightly soft and acidic.  You can get the same effect, namely a large, intelligent and interesting fish, if you go with midas cichlids or red devils.  If you want really big and beautiful, try Cichlasoma synspillum, sometimes called Theraps synspillum.  Either of those fish will probably really like your water.   

  The alternative is to go with East African cichlids, i.e., those from Lake Malawi and in particular Lake Tanganyika.  They like liquid cement which it sounds like you have.   You might consider a frontosa if you want large fish.  If you want smaller, there are literally a thousand such East African cichlids to choose from.   

  The best thing you can do is to try it out. Fill up the tank and get a  couple of fish to see what happens.  The biggest problem may be that many of the fish which are immediately available to you have become acclimated to less hard water than they were used to in the wild by being in other people's tanks.  You may find that wild fish do very well in your system.  If you decide to go that route, consider getting stuff directly from one of the importers, e.g., Old World Exotics (Laif DeMaison) in Florida.  Your local fish store can order from him.  BUT, try a couple of local fish first to see what happens and let me know.

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>