Sand bed replacement

[fishkeeprian]

Hi,

It I replace my substrate will it cause my tank to cycle again?

[thegrun]

Yes you can replace it but it should be done incrementally, 1/4 or 1/3 at a time waiting a week between removal/replacements. Use dry sand washed to remove the fines (dust) or it will cloud up your tank for days. It's best not to use "live" sand which can contain enough dead organics to kick off a new cycle.