In one of the photos above, there were bubbles on the surface, not scum.
I have been feeding the silvertips a varied diet to condition their colour further. Dad moved my younger sister's tank and used all except for one of the jugs of dechlorinated water. The tank is still evolving at its earliest stages, so I will add in more plants over time to make them feel safer. They're starting to shoal more often during the day. The light brightness are low, dimmed to prevent algae growth, and I can control its brightness over time through the settings.