Sea Shell and Coral in Fresh Water

Question
Ron:

I have a 10-gallon fresh water tank with a few tropical fish and I was wondering if it is O.K. to have a few large sea shells or corals in the tank as decoration?

Thanks for your help.

- Alex

Answer
Hi Alex,
 You can but they will slowly make the water harder and more alkaline.  That is fine for some fishes, e.g., East African cichlids, but not good for other fishes, e.g., West African cichlids or South American cichlids, many livebearers, etc.

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