Well it痴 not as hard as I thought. The gunk was coming from this panel on the overflow that just slides out the top. I wish I壇 have known that a year ago! Duh! This is my first overflow tank so I致e just had to learn a few tricks. I think I overdo it though. I知 told that I don稚 have to do the hoses and that the stuff that comes out won稚 harm the fish, but I think once a yr gives me peace of mind. I also like being able to see any dirt in the sump and not having to squeeze the bjesus out of those sponges. I just vacuum the bottom on occasion and it takes seconds to change filter socks. I was ready to do everything you suggested till I lifted that darn panel and heard the angels sing! Ha ha
Patty