White Flatworms

[swill]

I have a 300 gallon Fowler tank and noticed this morning that there are white flatworms in it. I did some reading and read that they are harmless and will usually disappear on thier own. I also read that they like to eat the brown flatworms. I have a 90 gallon that is littered with the brown flatworm, I'd like to take the white ones out of the 300 gallon (somehow) and put them in the 90 gallon. I'm wondering if anyone has tried this or would adivse against it for any reason?

Thanks!!