Cloudy water is a very common guppy tank problem, especially in newer setups or tanks that have had a recent “big change.” The mistake many people make is trying random clarifiers or doing massive cleans that reset the system. Cloudiness usually falls into three categories: bacterial bloom, suspended debris, or algae haze. Once you identify which one you have, the fix becomes straightforward.
Cause 1: bacterial bloom (milky white haze)
This often happens in new tanks or after overfeeding. The water looks foggy rather than “dirty.” The safest approach is patience plus stability: avoid overcleaning, keep feeding light, and ensure good oxygen.
Cause 2: suspended debris (you can see particles)
This comes from disturbed substrate, dirty filter media, or fine food. Improve mechanical filtration, reduce flow disturbance, and do routine water changes.
Cause 3: algae haze (green tint)
Green water is a light-and-nutrient issue. Reduce light duration, block sunlight, and control nitrates with consistent maintenance.
Fast safe fixes
- Test ammonia/nitrite: if not 0, correct immediately.
- Increase aeration: supports bacteria balance and fish comfort.
- Feed less: stop adding extra fuel for blooms.
- Keep routine steady: avoid stripping filters or doing 100% changes.
Cloudy water is usually a short-term phase or a feedback signal. Solve it by stabilising inputs and maintaining export, and the tank will clear without harsh chemicals.
