From a fellow angelfish lover here is what I did....I have a Scribbled and a Majestic angel in my 6 foot by 2 foot by 26" tall tank that is just under 200 gallons (just put in two golden butterflies and they are all getting along). If you get some of the milder mannered angels like these you can mix two or three of them in the 180 gallon but it is best to add the larger ones last. My Majestic is fine with the Scribbled (after the first few weeks), and was even fine with a Goldflake that I had that died of worms. I think in a 180 it is best to stay with the angels that stay in the 10 to 12 inch range like the Majestic, Scribbled, Goldflake, Regal, and even a Flagfin......these angels are not as agressive as a large Queen or French angels that grow to 18 inches which is too wide for a 24" wide tank IMO. You can have more than one of the smaller large angels like the ones mentioned if you put the biggest ones in last or add them at the same time. As for your French angelfish I think that it would be unhappy in a 180 gallon tank when full grown. My angelfish also get along with the clowns, fairy wrasse, blennies and royal gramma without problems. Don't limit yourself to just one jumbo (although pretty) French angelfish that is too big to be happy in the 180 when these others can live out their lives in this size tank. Lesley