Sick Flowerhorn Cichlid

Question
We have a 3 year old flowerhorn cichlid.  We used to feed her goldfish (we didn't know and the pet store never told us we were not supposed to).  About three months ago, she got very sick, stopped eating and stayed at the top gasping for air.  We asked the pet store what to do.  They recommended a full treatment of Metronidazole.  We did that.  She did get better, but only about 90%.  She started eating again (we're now feeding her cichlid pellets), but the back half of her stayed a dark color.  Then about two weeks ago, she stopped eating again.  She is now really dark all over.  Her belly looks full, but she won't eat.  Sometimes, she does gasp for air at the top, but not all day like three months ago.  When she's feeling happy, she sucks up the rocks on the bottom of the tank and moves them into piles.  She has not done that in over two weeks.  About two days ago, she started swimming in a circle all day long - it's really freaking me out.  We gave her another round of Metronidzaole, but it didn't change a thing.  On the first day of treatment, her excrement was long stringy florescent green mucus - not at all like her normal poops.  There is nothing else in the tank, no fish or plants - she kills everything, there are some rocks at the bottom.  49 gallon tank.  We clean the water every weekend - flushing about 1/3 of the water out every Saturday.  Please help, as silly as it is, we really love this fish and I am worried that she is suffering.  Thank you for any advice you can offer, I really appreciate it.

Answer
Hi Angie,
 It sounds like she has an internal infection.  These are tricky to diagnose and cure. The choice is yours.  You can try the various medications and see what works, but medications can be very hard on a fish. Sometimes, just doing a lot of water changes (e.g., 25% every day for four days) can really help the fish to fight the infection themselves.  

-- Ron C.
  rcoleman@cichlidresearch.com
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