Dalmation Lyretail Molly (Marble Molly)

Question
I have a 55 gallon tank that has been set up about 1 1/2 weeks.  I have an under gravel filter with 25 fish in the tank.  They consist of guppies, mollies and platties.  I purchased 2 Dalmatian lyretail mollies yesterday.  One of the mollies is doing fine, but the other one is staying at the top of the tank by the heater with his head up and his tail down.  If he does move away from the heater, he also swims in the same fashion (very awkwardly).  All my other fish are doing fine except him.  What can I do to help him, or am I fighting a losing battle?  I really didn't think he was going to make it through the night.

Answer
Hi Marcy;

It is probably in shock from being moved. Provide additional hiding places for him such as floating plants or something. Hopefully he will recover in a day or two. Look carefully at him to be sure he doesn't have any spots, blotches, torn fins or anything else that looks like disease or injury.

Your tank may be headed for some serious trouble in the next few days with so many fish so soon. It's still in the "Break-In Period" and it could be another 4 to 5 weeks until it's finished. Monitor the ammonia and nitrite to make sure they stay in a safe range as it gets through the next few weeks. Don't add more fish until ammonia and nitrite are both "zero". Here is a link to my article on new tanks to help you know more about what is going on and how to handle it;

http://www.xanga.com/Expert_Fish_Help

At Your Service;
Chris Robbins