salt water natural ornaments in fresh water tank

Question
I have a dried coral,sea sponge and conch shell in my fresh water tank that I am setting up.  Will these Old items hurt the balance of the tank?  I want to put guppies in the tank. please advise.

Answer
Hi O Chau
I don't know about the sponge, but the other two may raise the ph in your tank.  You could try setting them in a bowl with water.  Test the ph and let it sit for a day or so, then test the ph again.  If it changes, that's what's going to happen in your tank when you do water changes.  When you do water changes, and add the new water in, it may drop the ph level in the tank, but then those items/decorations will cause it to rise again.  This all will most likely happen fairly quickly, which cause ph shock in the fish and kill them.  Try doing that test first though, because your ph may be on the higher side anyway, therefore it may not alter it that much.

Hope that helps and let me know if you have more questions.

Christy