Are these flatworms planaria?

[Vizza]

I'm dealing with some tiny critters in my 16-gallon tank and I'm hoping they're not planaria. It's a planted tank, and I've never had much luck with snails in it, probably due to the soft water. I do have a lot of silt, though - my Extreme can barely keep up and I've had to start vacuuming once a week. I just noticed these little worms living in the substrate and I'm trying not to freak out about it. I've had issues with china mark moths in my tanks before, but these guys are new to me. I wish I could've posted a video to get a better ID.

[coltin]

Hard to say for sure without a clear picture. Planaria have a pretty distinct look - flat body, arrow-shaped head, and those beady little eyes.

If what you're seeing is around 6-10mm long and thin, living in the substrate, it's probably just detritus worms. They're harmless, show up when the substrate's dirty or water quality's off.

Anything longer than an inch, still living in the substrate, is likely an aquatic worm. Again, harmless.

[TankWarrior]

Hey there, no need to freak out. These little guys are pretty common in aquariums. They're not gonna harm your fish, but they might affect your snails and shrimp. You're on the right track with keeping the water clean and vacuuming regularly - that's key. They feed on decaying plant matter and leftover food, so just keep an eye on that. If you want to get rid of them, you could try adding some fish that love to snack on these worms. Livebearers like Guppies and Mollies are great for that, they'll help keep the population under control.