Group of Endlers in an aquarium with submersible heate, Java Moss and a sponge filter.

I do use heaters set to between 78-80 degrees F. for most breeder tanks. The fish in buckets and containers do not have heaters so the temperature stays between 70-76 depending on the room. Higher temperatures allow for faster growth and breeding but it also burns out the fish faster (that is they seem to age faster and die sooner). My endlers seem to breed just as well at the lower and higher temperatures. Babies take much longer to grow at the cooler temperatures but the babies that are born are strong and sometimes larger than those where the mother fish was kept at a warmer temperature. If you desire a large number of babies quickly, use a heater and set it to about 80 degrees F. Females will drop young about once a month. If you don't use a heater it will usually take a few weeks longer for a female to give birth as it takes longer for the eggs to incubate inside her..

If you do use a heater, please make sure to use a thermometer. A good submersible heater is fairly reliable but once in awhile a heater will go bad and fry your fish. A thermometer will usually warn you in advance. If you notice that the temperature is higher than it usually is, and there is not a good reason, such as an exceptionally warm day. Check your heater quickly for problems! This may save the life of your fish.