I don't think Ottos who like softer water would really be suited to the
pH the goldfish need. Also the same with the temp. Goldfish like it cooler (I have a koi and goldfish pond). And Ottos like it warmer and are very fussy about clean water. (a good mate for Discus).
Back to your situation. We have a similar one. My mom keeps her 2 goldies in a 30 gal tank with weekly water changes and everyone is super happy. Also she keeps it very cool. Lights out during the day and they come alive when the lights are on and its feeding time. (think they sleep more than we think) I think its normal for them to hang out and be relaxed. If they didn't wake up and act happy about dinner time. Then I would be worried. Cause they love, love, love to eat.
