Treating illness...

Question
QUESTION: Hi.  I am a new tank owner, I have had my 40 gal tank for a year now, as it was given to me by a friend.  I have a plecostamis, 2 bala sharks, 3 tetras (not sure which breed, they are grey in color with a black spot on the top fin) and a catfish.  I had 3 balas, and one just died a few days ago - I believe he had septicemia, as he had red streaks under his chin and just stopped swimming.  (Please forgive my ignorance) Again I am new to this, so I am worried about what will happen to the rest of my fish.  One of the tetras had popeye in one eye.  He developed it about 3 months ago and I treated the entire tank with Maracyn-3.  Today, I found him dead in the tank.  I have checked the water quality and it all seems good, just the water seems a little hard.  I put aquarium salt in about a week ago, but I am still worried.  (By they way we did a 50% water change after the bala died).  I guess I just need some guidance about what to do from here on out... I have spent hours looking online and reading other pages to get advice and am getting overloaded!  I am planning on 25% water changes monthly (should there be more?).  By the way, before you give me a hard time about the size of the tank and the balas, the one who just died was 10 years old and he lived his entire life in that tank...

ANSWER: Hi Deanna,
  You need to be doing much more frequent water changes. You should be changing about 25% of the water once a week, every week to keep the fish happy and healthy.

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>


---------- FOLLOW-UP ----------

QUESTION: Is that all?  Weekly water changes?  Won't that stress teh fish?  Also, this morning I looked at my balas and one of them looks like his eyes are swelling a little... will weekly water changes at 25% help with that too?

Answer
Hi Deanna,
  Frequent partial water changes do not stress fish at all, unless the water you are putting in is somehow toxic.  The best aquarium systems actually use flow-through water, i.e., the water is constantly changing.  

  I can't guarantee that more frequent water changes will fix everything, but I can guarantee that if you don't do more frequent water changes, your fish will have more and more problems.  

  The best "cure" for fish is to give them really good quality water and let them fight off most infections through their natural immunity.  If you start adding a lot of chemicals without knowing exactly what you are treating, odds are you will do much more harm than good.

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>