Finding whelks in tank

[haleyf1024]

So far I have found 2, and they have been caught and sumped. Any idea how to guesstimate how many more there are? I also found what appeared to be a baby whelk or nass snail, but since nassarius don't breed much in captivity I think it was a whelk, so he is also living in the sump.

 

[haleyf1024]

The ones in the tank haven't hurt any coral, fish, shrimp, crab, or anything else.

 

[60squared]

I thought the ones that showed up in my tank were fine too.....until I got a clam

 

[SpartaReef]

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