Foamy or bubbly surface
This looks like: organic film and protein froth — often feeding, dead critters, or lazy surface exchange
Why this happens
Protein skimmer vibes without the skimmer — organics churn at the surface when agitation meets waste. Small dead snails do it quietly.
What to do right now
- Increase gentle surface ripple with filter or air.
- Remove duckweed mats trapping foam temporarily.
- Search for dead snails or shrimp; remove.
- Skim with paper towel once safely — then fix root feeding.
- Retest ammonia because decaying protein raises it too.
What not to do
- Don’t dose “foam reducer” potions before removing waste sources.
Stop it happening again
Don't overfeed, keep the surface moving, and remove dead snails or shrimp promptly - foam is usually excess protein plus lazy flow.
If that doesn’t fix it
Persistent foam + sick fish → bacterial infections look again.
Catch this earlier next time — log your water parameters in App-aquatic. Free forever.
This isn't veterinary advice - it's a directional read to help you decide your next step, based on the most common causes. We can't see your fish, so pair it with a liquid test kit and clear photos, and see an aquatic vet or a trusted local fish shop for a valuable or seriously ill fish.