re: Fish keepers?

Get a Fluval or Eheim cannister or for more $ a wet/dry filter.
Water changes are crucial. Moving rocks can ease aggression. Always add multiple fish when introducing new tank mates. Adding a single to an established tank is almost always certain death with Malawi & Tanganyika cichlids as they are so territorial. Sometimes it helps to add new fish in the dark of night when everyone is asleep.
I did exotic and wild caught F0 African cichlids like Tropheus and Petrochromis over 30 years, just got tired of the never ending. maintenance. Had a 30 gallon in my dorm in Pentagon for a few years as an underclassmen.
2 things you can always get a smoking deal on via Craigslist: aquariums and musical instruments! People go all in and lose interest. Takes alot of time and dedication.