Ta Mac,
btw have you ever heard of small red worms tapering to white at the ends about 10mm long that live in the substrate of an aquarium?
I have such things that don't seem to be a problem and are only visible to me when gravel cleaning (each week). The clown loaches are regularly digging - I guess for these. And if any escape during cleaning they are soon snapped up by other fish - they love them!
Anyway they don't seem to be a problem - just wondering if you've heard of such things?