Rasporas dying

[stanleo]

I have had the same school of harliquins for over five years. I keep nitrates at 10ppm and pH at 6.4. 110 gallon community with other peaceful schooling fish and a mated pair of angelfish. I have slowly lost one at a time starting about 3 or 4 months ago. I went from nine now down to five and one is swimming lopsided. Could this be old age? No other loses for a couple years now.

 

[Colin_T]

Yes it could be old age.

What symptoms did the others show before dying?
Did you add anything to the tank a couple of weeks before this started?

Can you post some pictures and video of the fish?

How often do you do water changes and how much do you change?
Do you gravel clean the substrate when you do a water change?
How often do you clean the filter?