Your tank like mine and Paul's plus a few others I know are doomed, doomed I tell you and will fail in the next 100 years. Give od take a few 100 years of course.Here comes a youngster - born 1950 in march. No mechanical filters no cleaning of sump or whatever. How the tank looks - look at my build thread. No WC either. Running a revers flow DSB too
Sincerely Lasse