Where Are These Planaria Coming From?

[NeonBlueLeon]

Recently, a betta tank became infested with planaria.  There was an algae wafer I dropped in for my nerites that I forgot about for a few days.  Oops.
 
Since then, I had done a 95% water change (betta was taken out, don't worry), and the planaria population has decreased.  The big water change involved extremely thorough gravel vacuuming, rinsing of all decorations and plants, and wiping tank walls.
 
I am still doing daily 30% water changes in an effort to get rid of them.  After each water change, I barely see any planaria, but by the next day, the planaria population seems to grow.
 
Feeding has been decreased to nothing for the snails, and pellet by pellet for the betta.  There is no uneaten food ever left in the tank, and all poop is removed daily using a gravel vac.  There are no decaying plants in the tank either.
 
Where can the planaria be getting nutrients to reproduce from?

 

[frothhelmet]

Probably biofilm. If you want to get rid of planaria try flubendazole. Wont kill other inverts...

 

[micko]

Use a product called 'No Planaria'. Its apparently very good and safe for shrimp. If you didn't want to try this I'd suggest taking all your substrate out and giving it a blast with a steam cleaner. Either way will kill them off but the latter is more work.

Good luck.

 

[snazy]

Are you sure you have planaria or detritus worms?
Planaria is a carnivorous hitchiker you've introduced via plants/decor. They like meaty foods, not algae wafers. Fish don't find planaria tasty and adult planaria can attack small fish and shrimp.
Detritus worms appear after one overfeeds the tank and there's left overs, and regular maintenance+proper amount of food for the livestock will decrease the population, same as snail issues. They are a natural response to a problem and killing them at once can cause other issues.  Fish eat those readily by the way, if they catch them.
 
Planaria looks more like a slug, has arrow shaped head if you look with a magnifying glass.
Detritus worms are thin and swim in S shape kind of.
 
Both can be different colours.

 

[NeonBlueLeon]

Thanks for the replies.
 
Snazy, since posting this, I've actually concluded that they are not planaria.  I also said algae wafers, but it was actually the Hikari sinking wafers, made primarily of fish meal.  Further research of detritus worms made me think that's what they are.
 
Nowadays, I only see one or two worms free swimming, that snake through the water.  If possible, I chase them down with a chopstick and take them out.  No planaria sounds like it's harmful to snails, which I have two of.

 

[snazy]

The detritus worms are harmless. I wouldn't even bother chasing them around but if you fancy doing so...

  Same as snail infestations, they appear to deal with the consequences from us neglecting the tanks from time to time