Algae Confusion Water Propagation on pothos
What's Happening
Pothos propagators frequently misdiagnose light-induced algae on water roots as bacterial rot, leading to unnecessary interventions or discarded cuttings. Clear glass containers allow light penetration that triggers brown algae growth on root hairs - this appears as brownish discoloration but lacks the mushy texture, foul odor, and spreading pattern of true bacterial rot. The algae is superficial and non-pathogenic, while true rot affects the stem base and spreads upward.
How to Fix It
- 1
Diagnostic test: Gently squeeze suspected roots - algae-covered roots remain firm; rotting roots are mushy and disintegrate
- 2
Smell test: True bacterial rot produces distinct foul/sour odor; algae has no odor
- 3
Progression check: Algae appears as uniform surface coating; rot spreads from stem base upward
- 4
If algae confirmed: simply transfer to opaque container - no other treatment needed
- 5
If rot confirmed: follow full H2O2 protocol and repot; discard if stem base is affected
How to Prevent It
Use opaque containers, mason jars with sleeves, or cover clear vessels with paper/felt to block light. This prevents algae entirely while maintaining visibility for root monitoring. If using clear containers for observation, wrap with removable cover that can be removed briefly for checks then replaced.
Related Problems
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