Judging yr post having such great no of tanks, u r hyper-active person/just cann't sit down doing nothing. I think having GF is further better having sports car as a hobby. If you don't keep GF u would propably get something else.

You should change water/filter when yr family asleep/do things without require yr present (watching tv, shopping, etc). Always wife come first then yr GF, with this rule she won't be jealous. Anyway she should be grafeful, hubby having just fish not girl friends.

Yr tanks become multi-national company, u need a delegate some of daily routine to someone (maybe family/neighbour). If no help, got to install equip to auto-do-stuff (WC, feeding etc). Hopefully get yr friend hook on GF too, so friend join-in.

Just fact of life, being having will include burdens & sorrow if nothing will complain being bored to death.