27 gallons
Well first and foremost 6" in diameter would make an angel the size of a salad plate.... 10" would make an angel the size of a dinner plate!!!! Seriously grab a small plate from your kitchen and a tape measure... I have seen breeders with 4-5" angels and veils but honestly most small time fish people are lucky to hit the 4" mark.
Second I doubt the OP is buying large angels (10-15ea+), and I would be surprised if they are larger then a quarter.
Angels are almost as finicky as discus as far as water and their being prone to disease. Same family etc etc. That being said I doubt op could get 10 angels to max size. If he had a total of 10 quarter sized angels I would say in a year he would be lucky to have 6 remaining. Unless he is a master fish keeper (if he was he would know what paired with angels)
It is frequently done but not advised to mix angels with anything, they are like discus in that they should be kept species specific.
I bread angels for years... I'm telling you that it can be done but is not advised to keep them with anything else. They are chichlids and thus do slightly better if they are heavily stocked, this reduces aggression or more or less spreads it out say you have 10 nips a week if the 10 nips happen to 10 fish everybody lives if the 10 nips happen to 2 fish everybody dies.... They should also be kept in a Harem type grouping with the females out numbering the males. They do pair but forced pairs don't often work.
Angels are actually ideal for hex tanks because unlike most other cichlids they swim the entire tank they actually NEED to be able to go up and down, they are one of the few fish that actually DO BETTER in a tall tank.
Personally I would plant the center of the tank with TALL plants that go all the way up and leave the parameter clear so that the fish can swim in circles. I would throw a couple fancy plecos and more angels in there and call it a day. The plants will help improve water quality particularly because the ratio of surface area to gallons of water is lower in a tall talk thus the tank needs extra O2. I would run my bubbler lines right down into the center of the tank where the plants are so you have a bubbling garden of sorts for the fish to swim around.
I would use only high quality food and change water a minimum of 1x a week. Never doing more then 25% change.
Sorry bassbonediva but after all of my years as a fish keeper I don't really see any new fish keeper keeping very many angels long term, they just aren't that hearty. some will go the distance but you will have so much time between now and then that there will be casualties along the way.
The Angel Fish
