I only have 5 fish (3 clowns and 2 damsels) in my 125g.
I had originally went w/ a fish only tank and the nitrates at one time were above 80ppm. Removed the bio balls, swapped the cc
for a 3-4" sandbed, upgraded the lights for the fuge, added more macro algae, added 130lbs more lr
and lowered the amount of feedings.
I'm sure I could have done more water changes to get the nitrates lower faster but I figured this is a more long term fix. Plus, I wanted to grow a couple macros in the main tank as well.
I was gonna get more corals yesterday but the two places I went had nothing that caught my eye. So I guess I'll be waiting anyways.