(Old age is not meant here :))
The Triops usually die during or shortly after the Nauplian period. You will either find too little food or the water will tilt because of overfeeding, which is the sure death for the triops. Another cause of death in the first few days is an excessive temperature fluctuation. Here, the water temperature may only change by a maximum of 2 - 3 ° C.
Any remaining food must be removed daily, otherwise it will mold and foul, causing a strong nitrite development. Too much nitrite in the pelvis is fast lethal. This is why a partial water change has to be carried out regularly.
The main watch for a failure of the breeders is the overfeeding and their consequences. Never feed more than described above.
A fast day every week is also no problem for triops.