If you feed silversides x1/week you can do a water change on that day afterwards, but your filtration system should be strong enough to handle it regardless. Switch between frozen foods every meal so if you feed daily: shrimp one day, next feeding fish, next feeding squid head (removed beak and hide vitamin tab), next feeding shrimp, silversides.....2 rest days. If feeding x3/week you can feed shrimp one day, silversides or other fish, and shrimp again. These are just examples. I personally do not feed live and stick to frozen.