I've never kept Angelfish, but have kicked around this forum for the best part of two years, (never mind my joined date, this is my second reincarnation), and have read every thread in those two years, including a ton on Angels. So most of what I'm going to say is based on reading these posts, or based on general cichlid behaviour.
With that said, if some one like apistomaster
or star rider
says something different to what I've said, believe them.
So are you looking for pairs
? or just a school of Angels? It's natural instinct for cichlids to pair up and mate, so it's often hard to have a proper school of cichlids like you sometimes see in documentaries on tv. Many SA cichlids, Angels included, form pair bonds that last the pairs life span.
Once two cichlids pair up, they will claim a territory. The size of this territory often depends on the species of cichlid and it's size. Some cichlids when not spawning, will interact with the other fish in the whole tank, but when spawning, they vigorously defend thier area of the tank. Some other species of cichlids defend thier territory all the time, whether they are spawning or not. I have read on here a number of accounts where pairs of Angels have defended thier part of the tank all the time, and not just when spawning. Again I have read here of pairs of Angels claiming a territory that measures about 2 feet in length of larger community tanks.
Also many SA cichlids show higher levels of aggression towards others of thier own species, than towards other cichlids in general. I believe this is true of Angles. That's not to say an individual or pair, won't be aggressive towards another type of cichlid that enters it's territory.
So with the above information I would guess two pairs of adult Angels would be a comfortable number in a 75 gallon tank.
Many people advise buying a larger number of juvenile Angels and letting them grow and pair up in an aquarium, and once you have the final number you desire, you return the rest to your LFS for store credit, or try and sell them yourself. Like many SA cichlids, juvenile Angels will scool together and not show the levels of aggression that adult Angels will.
As for possible tankmates. I like adding fish from the same geographic area, sticking to what's found in thier natural ecosystems. Usually with a little research, it's easy to figure out some basic guidelines that will and won't work.
Have you looked at the 75 gallon cookie cutter setup here
at C-F? They have one for Angelfish. Though with good filtration and a propper water change schedule, I'd up the number of tetras and catfish.
So I would be looking at adding a school or two of tetras that are large enough not to get eaten by adult Angels.
As Angels inhabit the mid-water of the tank, you could look at adding some smaller, bottom dwelling cichlids. The cookie cutter setup recommends 4 Bolivian rams
, these are a very good, sociable dwarf cichlid. Or you could look at 4 dwarf acaras
, or a trio of Apistogramma
As for catfish, what do you have in mind? Again the cookie cutter recommends some corydoras
. These guys are very good at cleaning up uneaten food. Or you could look at a couple of smaller L#number
, fancy plecos. Up to you if you want a vegetarian variety, or one that eats meat (usually prepared foods like bloodworm, shrimp, pellets, etc, not live fish :lol: )
Since you are wanting plants in your tank, I would strongly suggest 6 otocinclus catfish. These are a small algea eating catfish, that will help controll the levels of algea on your plants, driftwood and glass.
I hope this provides some valuable information, and if I've included some wrong information, the other regulars and Angel keepers will correct me.