Worms in fry tank -help!

[FishOCD]

There are half inch long thread-like white worms inching on the sides of my fry tank. What are they and will they hurt the fry?

 

[Allivymar]

Quite possibly they are nematodes or planaria; harmless but icky looking. They usually show up when there is an abundance of nutrients. Double up on the gravels vacs to reduce the leftovers and it should help reduce the amount of nematodes/planaria.

 

[FishOCD]

Thanks! I've done careful water changes but been skittish about cleaning too thoroughly for fear of killing the babies with the vacuum.