ANSWERS: 1
  • New sand goes in first, and live sand goes on top of that. Do not go any deeper than 4 inches total on top of an undergravel filter. If you do, you make get pockets of CO2 and methane gas. And actually sand is not a good biological filter media by itself. It tends to pack, still causing a build up of methane and CO2 gases. If you run your fingers or a stick through the sand and bubbles rise, that is the gases. They are toxic to your aquatic marine life. You should mix in some crushed coral or dolomite. :)

Copyright 2023, Wired Ivy, LLC

Answerbag | Terms of Service | Privacy Policy