Input appreciated

[BKohlman]

We have a 55 gallon aquarium with livebearers, bristlenose plecos, cherry shrimp, and cories. My wife would like to add a bigger fish to our aquarium, what would our options be, if any?

[lefty o]

siamese algae eaters a pretty community fish friendly, and get a tad over 5" when grown. 2 or 3 of them would go nicely.

[Fish Folk]

That's a pretty tank! The question is a bit hard to answer without knowing more about the parameters you keep things at right now, and what your regular maintenance schedule it like. 

The general rule is true: "If a fish can fit in another's mouth, it will eventually go there!" 

Angelfish and Discus have smaller mouths -- despite being Cichlids. But the parameters for Discus . . . 86-degrees Fahrenheit, and pristine water quality often do not fit well with livebearers who prefer temperatures in the 70s. Angelfish may be a bit more tolerant of temperatures under 80-degrees; but they can sometimes get more aggressive to tank mates than discus. Just the same (someone here will disagree) I think you could get away with a pair of Koi Angelfish in this tank, as long as you keep the water clean, do weekly water changes of 25% or more, and keep the temperature at about 78-degrees. Maybe buy them at small or medium size rather than huge, fully grown.