heavy breathing

Question
We have a 60.gal. tank, 2 Oscars,2Jack Dempsys,2 jewel cichlids and 3 African cichlids, last week we cahnged over to a Rena Filstar xp.Its good for 75 u.s Gal.My problem is though that as our Osacrs get bigger we notice that they're hanging out at the top of the tank and they're breathing extremely heavy.Our other filter system we did not like, it was interior and had tubes run along the top of the canipy that had 4 canisters for bio,carbon, and what ever else.We have to constantly change the water now.Up to 25% changes, it helps for a bit then there right back to breathing hard.We feed them once a day now, we were feeding twice a day but thought once a day might help but no...do we need to let the bios build up? my wife and i would greatly appretiate any help, we love our fish and do not want to loose them,especially my Oscars.Our water is always milky and its just not fun to watch, its really quit frusterating,,

Answer
Hi Lee,
  There are a couple of things happening here.  First of all, oscars are very messy fish. They are wonderful and interesting, but they are also messy so they often need more filtration than other fish.  When I have a tank with that kind of situation, I put two filters on it and that really helps.  

 You will still need to change 25% of the water, once a week, every week, to keep the tank happy and healthy.

 In addition, however, you should always have an airstone in a fish tank, particularly one with large fish like oscars and Jack Dempseys. This is quite separate from the filtration system.  Adding that will likely immediately take care of the heavy breathing.  There are solutions that might cover both problems, namely putting in an air-driven sponge filter.  That will both add the oxygen and provide additional filtration. That is actually what I do for most of my tanks.  

-- Ron
  rcoleman@cichlidresearch.com
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