SCHEDULER
Water Change Plan
How much and how often to change water — based on tank age and stocking load.
25
% weekly
≈ 5 gal per week · 1× /week
Why water changes matter
Partial water changes remove nitrates, replenish minerals and keep pH stable. The science: weekly 25% changes outperform monthly 50% changes for fish health — smaller, more frequent changes avoid shocking the biological filter.
| Tank state | Weekly change |
|---|---|
| New tank, cycling | 20% (avoid disrupting cycle) |
| Established, normal load | 25% |
| Heavy stocking | 30-40% |
| Overstocked / sick fish | 50% + treatment |