Yikes! That's bad... You should do a water change to bring it down, if you haven't already.
Are you new to keeping an aquarium? And is this tank newly set up? Is so, then you probably need to check out the threads on cycling a tank.
http://www.aquariacentral.com/forums/threads/freshwater-cycling.84598/
If you've had this tank running for more than 3-4 months, there are other things we will ask to get an idea of what's going on.
What is your normal maintenance routine?
What kind of filtration do you have?
How many fish do you have, and what kind do you have?
What are your water parameters? (Ammonia, nitrite, nitrate, pH, hardness, etc - with a strong recommendation to get a liquid test kit.)
Are you the only one taking care of this tank?
Also, if this is an established tank, did you change out your filter media when you did the water change to remove the salt?
Sorry if it seems I'm being nosy, but as Freshy said, there are so many things to consider. We want to help, and the more details we have, the easier it is to figure out what's happening.