There is no filter, pump, co2 whatsoever. I don't even bother to change water after a few months, just add water, turn on the light every night, and add food every few days.
The whole thing is sitting at the back of the guest toilet in my home. The system is still going strong today, although does not look too nice now. One of the fishs - a Golden Mustache, has survived 3 years and still very active.
