How long will blackworms (tubifex worms) stay alive in the aquarium?

[jread]

I fed some live blackworms (a.k.a tubifex worms) to my dwarf puffers tonight and noticed some of them buried down into the substrate. I looked again later and noticed them crawling around in there, making tunnels, etc.

How long will they stay alive in my tank? Will they live until they're eaten?

[Z Man]

Yes, they will live a long time in the substrate. Possibly even breed. I have already removed fiber filled filter boxes and let them set around for a few weeks before cleaning them out and found blackworms alive in them. A floating blackworm feeder is availble in most store that sell blackworms. It is cone shaped & looks like a sieve and the worms can slowly work their way through the little holes. It's not good to over-feed blackworms as a general rule.