Oscars and hole in the head

Question

-------------------------

Followup To

Question -
I had two large oscars and a large plecostemus in my 125 gallon tank for several years and was constanly pestered with hole in the head on the oscars.  It never really went away completely but was better at some times than others.  Those fish eventually died while the pleco seemed to be fine.  I recently (approx. 6 months ago) bought several fish from a woman that had them.  There was a bala shark, a red finned shark, jewel cichlid, cori, and two large oscars (about 12 inches).  All was fine for about 3 months when the bala shark died suddenly and one of the oscars developed hole in the head seemingly overnight.  I have been doing regular water changes of 50% once a week.  The nitrates were high for a short period of time, (80 ppm) but have been about 20 ppm for a week and the oscar with hole in the head healed some but still looks pretty bad.  The other oscars seems fine except he quit eating, been about 5 days now. The ph is 7.8 to 8.2 whenever I check it and has been that way as long as I can remember.  Ammonia levels are at 0.  I do not have a nitrite test kit and I live in pretty rural area and I'm  limited as to when I can get to a decent pet store to get one. I would sure like to not slowly kill two more fish over a long period of time.  The jewel cichlid,the red finned shark, and cori seem fine. The pleco has always seemed fine and I've had him for about 7 years. I really enjoy the Oscars and would like to learn how to keep them healthier.  Any help you could give would be great. Thank you, Ron.

Answer -
Hi Ron,
 Is it possible that you might be feeding them a little too much (that would put a lot of nitrogen into the water and promote hole in the head).  50% once a week is really good in the water change end of the things.  

 The other possibility, and I hope it isn't the case, is that you are on well water and that your well water is already very high in nitrogen.  This happens here in parts of central California, particularly in areas with lots of agriculture and lots of irrigation.  Is that possible?

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


I am not on well water, but I do live in the desert, we collect our water off the surface of the ground that is very alkaline and the water changes depending on the amount of rain and/or lack of it, but the ph always seems to stay at a constant high level of 7.8 to 8.2.

feeding them too much is a definite possibility.  My wife says i fatten up anyone around me including my animals.  That is easy fix to cut back on the amount I feed, but what do I do to treat the hole in the head they already have?  Or will it clear up on its own when I get the water quality right?  Thanx for your time.  Ron

Answer
Hi Ron,
  Try cutting back on the food a little.  An oscar should be just a little lean, not thin, but not heavy.  They should always be very eager to eat.  

  Hole in the head seldom clears up completely, but what you want to do is to at least stop it from progressing.  Improving the water should do that.  

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