Angel Fish Question.

The 55g tank will not be overstocked with four angelfish, depending of course upon the numbers of other fish and their compatibilities. But you could have issues.

Are you certain the two angelfish you have are both male? Is one of them dominant and the other submissive? How old are they, or how long have they been together?

Aside from the above, adding angels sometimes works but often doesn't. This is a shoaling fish by nature, meaning it lives in small groups and they establish a distinct hierarchy within the group. Once two or more fish are in an enclosed aquarium, this hierarchy can become set, and any intruders are unwelcomed. Adding females if both fish are males is a bit different, though not all males will accept all females, so trouble may still occur. If you want to breed the angelfish, it is best to let a male select a female (and then remove them to the breeding tank) from a group of fish.

And BTW, mature angelfish are able to eat neon tetra, depending upon the fish and their environment.

Byron.

I've had better luck adding small angels to a tank with mature angels... Often larger angels will be chased pretty aggressively. I have found this to be true of African cichlids too. It seems like the small ones aren't seen as competition for food and territory, nor are they seen as potential mates. The get chased in a curious manner, then pretty much ignored.

If a breeding pair forms you are in for trouble with that stock in my opinion.

Mature-sized angels are known to eat Neons.

hit or miss with the neons.. they are safe in one tank but become fodder in another.

how were you able to sex the angels??

the species are difficult to sex as the males and females share many traits.. theo only sure fire way to to vent the fish or look at the ovipoistor when they are trying to breed.
in any case you can add 2 more angels, after quarantine procedures, and watch how they interact.

beware of the pleco, from my experience when the pleco grows larger they are getting lazy at cleaning up the algae and prefer slime coating of other fishes.
try observing your pleco when it's dark (turn off the aquarium lights and the room lights, leaving only night light). I saw my pleco chasing, latching, and sucking the body of my angelfish despite the angelfish struggle to get free. ever since that day i never keep pleco in any of my aquarium. nowadays i uses 2 nerite snails and some ghost shrimp as my algae busting crew in my angelfish tank.

So what did you end up doing with your angels?

if i saw my pleco doing that to one of my fish...well lets just say anyone for fresh sushi?