No, if you did a flush and a bunch of goo came out, you are done until next time. Don't worry about the residue unless it is starting to overcome the filter.
Yesterday, after 2 years of my improved design using only fencing, I had to hose off the overflow snorkel because of a build up. That took 2 years with a huge fish load to happen.
Yesterday, after 2 years of my improved design using only fencing, I had to hose off the overflow snorkel because of a build up. That took 2 years with a huge fish load to happen.