There's a good chance that there was still crap in the lines following your tank cleanout, and that your 'new' filter is already plugged... simplest thing now is to change it. I'd flush all lines before reinstalling the next filter.
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)