When a guppy tank starts looking messy, the natural instinct is to “deep clean everything.” That’s also how many people accidentally crash their tanks. The biological filter lives on surfaces — especially inside filter media. If you scrub and rinse everything under tap water, you can wipe out beneficial bacteria and trigger ammonia spikes. The goal of cleaning is not to sterilise the tank. The goal is to remove excess waste while protecting the biology that keeps fish safe.
What to clean regularly
- Glass: scrape algae from viewing panels as needed.
- Substrate zones: light vacuum in waste-collection areas.
- Pre-filters/intakes: remove gunk that blocks flow.
What NOT to clean aggressively
- Filter media: don’t wash under tap water; rinse gently in old tank water.
- All decor at once: avoid stripping all surfaces in one day.
- Substrate deep cleaning: massive disruption can release trapped waste.
A safe cleaning schedule
- weekly: small water change + light substrate tidy
- as needed: glass scrape and plant trim
- every few weeks: gentle filter rinse (only if flow is reduced)
The “crash prevention” rule
Never clean everything at once. Spread deep tasks across weeks. Keep fish safe by keeping the bacteria safe.
When cleaning is consistent and gentle, guppy tanks stay clear without drama. The best tanks are not the ones cleaned hardest — they’re the ones cleaned steadily.
