Group of Endlers eating zuccini in a bath tub.

My endlers have been kept in all types of tanks and containers. Adults have been housed in everything from 2.5 gallon tanks to a 35 gallon bath tub. Babies have been housed in 2.5 gallon to 4 gallon plastic buckets or bins with a bunch of java moss. Once gender can be determined, they are moved to adult tanks to either continue breeding or to be sold. I would suggest a minimum of a 5 gallon tank for even a pair of endlers since they will eventually have the babies and babies need clean water and space to grow properly. A 10 gallon seems to be the best size if you want to keep multiple pairs. Endlers are not picky about their housing arrangements and seem to do well in almost any container over a gallon AS LONG AS THE WATER IS KEPT CLEAN! If you change 25-50% of the water with aged/conditioned water each week, your Endlers should do well.