imo a eel is a bad idea.. not only do most of them come from 7.0 range PH's ( there are exceptions elpisifer, and the rarer plagosi (sp?) are actually from lake Tang. ) Tire Tracks can get over 30"+ and outgrow most tanks. Peacocks will stay smaller in about the 12" range. Both will potentially eat fish. I have 2 peacocks in with my guppies and they help control the fry but do not erradicate them. Also depending on the aggression levels of your Africans, If the eel can't hide. They can and will rip it to peices. Syno's would be a "hardier" solutions imo, But if your interested in the eels deffiantely do alot of homework first. I adore my eels, not gonna lie. But they are the neediest of my fish in reguards to care in general.