Pitting and missing scales and more

Question
Hi Ron, I have two Red Tiger Oscars (approx 5 inches) in a 55 gallon tank with 160 gallon per hour bio-wheel filter. I keep the water around 80 degrees Fahrenheit and have the light on a timer from 10am to 11pm 365 days a year. I feed with Cichlid pellets and approx. once a week frozen beef heart. I do water changes about every 40 days at 30%. The nitrate and ammonia levels have been consistently fine. Tank mates include two gourami's and two pecostomus. Four issues. 1. The Oscars have continuous reoccurring pitting and scale missing all around the mouth and eyes. 2. One Oscar i believe ate a recently introduced catfish/catshark? (I let a roommate get a fish), and now is continually opening and closing it's mouth. I believe it is unable to swallow what it intended. Is there any way to fix this? 3. One Oscar has a ripped dorsal and pectoral fin. Do these heal or remain separated? 4. I have had the Oscars almost two years, should they be larger, and what could impede the growth process i might be doing inadvertently? Thank you for your time!!

Answer
Hi Kevin,
  You need to be doing much more frequent water changes. That will help with #1 and #4.  You should be changing 25% of their water once a week, every week.  

#2: If there is something stuck in there, eventually it will break down.  I don't encourage trying to do surgery on the fish unless it is really obvious that there is something stuck in his jaw.

#3: Whether they will heal or remain separated depends on how deep the split is. If it is just near the end of the fin, it will likely heal. If the split goes down to the base, it will likely remain separated.

-- Ron
  rcoleman@cichlidresearch.com
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