Planaria (or nematodes) in a fishless tank?
Yesterday I started noticing small white worms, maybe 1/4 to 1/2 inch long, swimming freely in my water or clinging to the glass. All signs point to these being planaria. I'm not really overrun with them, and they're kind of fascinating, but I wonder.
* Will they harm my betta fish when I get him? Either getting in his gills or giving him a tummyache when he eats them (as I imagine he will)? He'll just be a baby fish still when I get him, barely 10 weeks, and I feel a bit overprotective.
* Where did they come from? I use RO water in this tank, it's all new substrate and filter and such, so I guess they hitched a ride with the plants or driftwood?
* What are they eating? I read that they come from overfeeding the fish, or from other ammonia overgrowth, but I'm not adding any food period, and my ammonia is at zero.
I'm guessing that a water change (I plan to change 25-40% later today) will help discourage them, but I'd love any input that people might have about these apparently spontaneously generated life forms!