Detritus worm or planaria?

[Thermal]

I finished setting up a 5 gal yesterday, and did a small water change today. Then I noticed these white worms on the glass, I tried looking them up and the most common answers I got is detritus worm and planaria. I don't know which worms are the ones on the glass, I read that detritus worms are harmless but planaria are bad for shrimps and snails. Currently the only things in the tank are bladder snails, if these ended up being planaria are they a threat I should get rid of? I don't know where these came from, I'm guessing they hitch hiked.

Here are some pics of one of them, unfortunately this is as good as it gets for quality.

 

[Colin_T]

Is the pointy part the head or the round part (which way is it moving, up or down)?
Pointy head can be a worm like planaria but with a different name (starts with R I think).
Round head worm is detritus worms.

 

[Thermal]

Is the pointy part the head or the round part (which way is it moving, up or down)?
Pointy head can be a worm like planaria but with a different name (starts with R I think).
Round head worm is detritus worms.

yes the round part is the head, and the tail is the pointy part. I don't know if its visible in the pics but the tip of the tail (pointy) is mostly transparent

 

[Seisage]

The pictures you posted are definitely rhabdocoel flatworms. Completely harmless, but perhaps a bit unsightly if you have a lot of them in the water column or crawling on the glass. Some fish will eat them, I think. I had quite a few in a new-ish tank and they all disappeared once I added some neon tetras.

Detritus worms are usually larger and are brown or reddish in color, and they don't really crawl on the glass