Who Gives A Fish Forums

whisker wrote: ↑Thu Aug 07, 2025 1:09 pm How often do you guys replace filter media? I heard old sponges can harbor parasites.

Never replace it all at once—just rinse in tank water during changes to preserve beneficial bacteria. If you're dealing with velvet, though, boiling the media or replacing it might be necessary after treatment.

My betta got velvet once after a power outage messed with the heater. Now I keep a battery backup for emergencies. Lesson learned—stress is a killer!

Prevention's cheaper than treatment. Invest in a good heater with a reliable thermostat, and check temps daily. A digital thermometer's worth its weight in gold.