It isn't the parasite itself, but clear stool is an indication of a tapeworm. I would suggest praziquantel or prazi-pro. But wait to see what others got to say first
Are you feeding the ray worms ?
My rays have always had poops like this after changing foods sometimes earthworms sometimes shrimp sometimes stress. I'd not worry if it eats let it eat leave it alone for a bit.
Just got it yesterday but I think the seller was feeding it worms. I just put her in yesterday and shut the lights. I'll see today if she wants some food. Thanks guys.