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Water Change Schedule
When in doubt, do larger or more frequent water changes. When done correctly & consistently, this will prevent and solve most of your problems.
The Three Phases
From a brand-new tank to a fully stable one.
Phase 1
New Tank
Weeks 1–8
Week 150% daily
Week 250% every 2 days
Week 350% every 3 days
Continue this pattern until…
Weeks 7–850% weekly
Phase 2
Growing In
Months 2–6
Everything going well50% weekly
Okay, not fully confident80% weekly
Issues arise (algae, instability)50% twice/week until resolved
Phase 3
Fully Stable
6+ months
Default50% weekly
This should allow you to sustain growth with minimal problems. More frequent or larger changes will always help, but are not required at this stage.
Definition of "Stable"
New tanks generally take about 6 months to become fairly stable.
A tank is only considered stable when both are true:
- Plants and livestock have been consistently healthy for 2–3 months
- Missing a water change does not significantly increase algae
Default Upgrade (Safer Option)
My current standard
If you want to reduce risk, increase all 50% water changes to 75%.