I have a pair of mollies that I have had for 2 months in a 20 gallon aquarium. They were very happy during this time, and even had babies. Recently, the male started to sit on the bottom so I transfered him into a 5 gallon hospital tank. This tank was house to a pair of zebras that are now in a totally different (third) tank. Now the female molly has been acting the same way, so I transferred her to the hospital tank also. The readings on both tanks are 0 ammonia, 0 nitrites, and low levels of nitrate. Both mollies spend all day sitting on the bottom of the hospital tank, where as they used to swim around actively all day long. They will swim to the top and eat when I give them food, but then promptly return to sitting on the bottom when they are done. I have added a bit of salt to the hospital tank after reading that mollies sometimes prefer salt in their water, but it does not seem to have changed their behavior after about 1 week. They do not appear to be suffering from any diseases and still look the same as when I bought them. I'm running out of ideas and was hoping that someone might have more suggestions.
Thanks for your time and responses.
Thanks for your time and responses.