knifegill;4948812; said:How many water changes are you doing every day to keep your nitrates below 40ppm? Oscars even need less than that, at around 20ppm. So just imagine, if ONE Oscar in a 75 gallon tank being fed every other day can easily push the nitrates above 50ppm in a week, what is the animal mass in your current tank capable of at adult size? The goldfish alone will outcompete the filtration in another six months. How is a 125 gallon tank supposed to make a dent in numbers like that? You've brought sticks to a swordfight and now you're in a losing battle for your fish's lives. Best move is to ditch the pacu, goldfish and pleco as they are your worst enemies. The Oscar will happily eat much of what's left for you after that, thank goodness.
wat.