Yes it is big enough for two retics. Most retics don't get much bigger the. 12 to 14 inches if you are lucky. Just keep up on your water changes and they would live happy life in a tank that size. But like others have said don't need it that tall but it won't hurt if it is either. We have raised, bread, and sold retics for yrs. and honestly as long has someone keeps up on the water changes you can keep 2 retics in and 125 for life without problems. Just the more water volume the easier to keep the ammonia level down. Hope this helps
