My Nephew has had a single yellow lab for the past 7 or so years now in a 29g tank. He started with a few cichlids in the tank when it was new back 7/8 yrs ago and ended up with just the single lab after it killed the other fish (his lab was pretty aggressive if you can believe that). I wasn't back into fish at the time so I wasn't able to help him decide on a tank size or stocking and such so he ended up with only a 29g and blue gravel and the tacky decor in it

Yesterday his lab finally died (old age I believe) and I didn't think he was even interested in fish anymore now that he's just started college, I kind'a thought he was just gonna get rid of the tank now that the fish died so I told my sister to ask him if he's gonna get out of it now...or if he was interested I could redo his tank for him with a 3D background, sand and give him three of my yellow lab fry I have in my grow out tank for it. To my surprise he jumped at that offer.
So now I have infected my niece (she has a turtle) and now also infected my nephew

Next is to get him to step up to a 55g soon lol