How to recognize them
Look at the front glass at night with a flashlight: planaria glide smoothly without wriggling, and the head is shaped like an arrowhead with two dark eyespots. Detritus worms, by contrast, are thread-thin and wriggle. Cut a planarian and each piece can grow back into a whole worm, so crushing them on the glass spreads them.
Reduce them without chemicals
- Feed less and remove leftovers after a couple of hours: planaria boom on surplus food.
- Trap them: a small piece of raw meat or a pellet in a jar or a commercial worm trap overnight, emptied in the morning outside the tank.
- Vacuum the gravel and change water.
- In a fish tank, many small fish eat them; in a shrimp-only tank that help is missing.
When to treat
Treatments are sold for planaria in shrimp tanks. Read the label for every animal in your tank: some are not safe with snails, which are part of many shrimp tanks, so move the snails you want to keep to another tank first and keep them there until the treatment and the water changes on the label are finished. Dead worms, and any snails the treatment kills, foul the water: change water and test ammonia in the days after. Cherry shrimp care · Breeding cherry shrimp.