Who Gives A Fish Forums

The key is to do it gradually. Remove about a third of the old substrate at a time, replacing it with the new sand. Space it out over a few days to avoid shocking the biological filter. Keep an eye on ammonia levels, as disturbing the substrate can release trapped waste.

flutista wrote: ↑Thu May 08, 2025 10:50 pm Thanks, mikero. I'll try that. How long should I wait before adding the fish back in?

After rinsing and scrubbing, let the tank air dry for at least 24 hours. Then fill it with dechlorinated water and run the filter for another 24 hours. Test the water parameters to ensure it's safe.