[bevsies]

Hello fellow betta lovers,
I have a question regarding (unwanted?) worms that gather on the glass in my tank (pic below).
I first noticed them wriggling around a few months ago. I did a bit of research and concluded that they were probably freshwater nematodes. They range in size from about 2 to 6mm long, they're white, extremely thin, and wiggle around like water snakes. My betta gobbles them up and his poo is healthy I'm not worried about stomach parasites.
Lately however, they've been multiplying and getting more adventurous. Their population explosion is probably because of my betta being in a separate quarantine tank so he can't eat them (he had a bit of fin rot). As for the adventures, add shown in the pictures, the worms (nematodes?) gather on the glass above the surface of the water. If I splash them or push then back into the water, they go right back to wriggling, so they're not going to die up there.
So my question is, what are they doing up there?

 

[olgamc]

They could be detritus worms. Detritus worms are harmless, they live in your substrate and filter and help break down waste. So they are actually good. However, if they are coming out of the substrate that could mean two things:

1. Your substrate is anaerobic (lacking oxygen), so you should poke it.
2. You have a population explosion due to too much waste, so you should vacuum regularly and clean your filter.

 

[bevsies]

Yes, those little swirls on the glass are worms, not roots.

 

[bevsies]

Ahh, that makes sense. My tank just finished cycling and finally posted nitrates the other day., and because my little fishie is in the QT I purposely did not clean the 10-gallon to let the cycle finish. I even picked up poo from the QT and put it in the 10-gallon.
My substrate is gravel, but I'll poke around in it. And I'll definitely be cleaning the tank before fishie goes back in.
As long as they're not harmless, I'm happy. Thanks!

 

[olgamc]

Welcome. Google detritus worms just to make sure that's what they are. Now that you posted a picture, they look a bit thicker than a detritus worm, but I am not an expert.

 

[bevsies]

Google images seem to match what I have. They're definitely not planaria, who are also coming up in "detritus worms" Google image results, but I think they probably are detritus worms.

 

[olgamc]

Yeah, planaria are easy to tell from detritus worms because of how they move. Detritus worms wiggle like snakes and planaria glide smoothly like slugs, so yours are definitely not planaria. Planaria are also harmless by the way, just hard to look at.