[musrusticus]

What kind of fish are you keeping in this aquarium? I'm tempted to suggest a bottom feeder like a cory cat; supposedly they love worms and are constantly scouring the bottom of my NPT for food. Those worms may be too big for them to handle, though. Snails might be a potential solution, too. They'll eat fish eggs so I would think they might enjoy worm eggs as well. Trumpet snails may or may not burrow deep enough to get at them, though.

If nothing else, you could also remove the plants/fish and dose the aquarium with copper sulfate or something similar.

I'm far from an expert, though, someone else will likely have better suggestions.