Here's md5 of a password with 21 chars
2061bf778a5cb9d7f72c55b09c46ba87
It's not even salted. Should be no problem no? You can do it fast since you probably have thousands of members when you were able to evaluate how big everyone's password is
From your answer i see you dont even understand what a salt is, or what is it's purpose.
Salt is used to make the redundancy on hashes even bigger. For example. "A" will always give a hash of 7fc56270e7a70fa81a5935b72eacbe29, so someone somewhere might have stored that same hash and saved it as "A", and someone might be able to reverse it by finding it, let's say, on google, or running it through hash breaking algorithms. Salt is invented so that each vendor/software platform could make up their own "salt" that could produce a different hash for "A", so that without knowing the salt, you can't replicate the hashing algorithm.
But still, password hashed with or without salt, you CANT KNOW ITS LENGTH.
so you were storing them plaintext?