Yes — with Endler's livebearers, stocking is not an event, it is a process. Females drop broods of fry at regular intervals, males are in near-constant courtship, and a colony started with a handful of fish can fill a tank within a few generations. Memory cannot track a population that renews itself monthly. A log can, and it turns surprise overcrowding into planned management.
Stocking records for a self-renewing colony
Date each brood you notice and estimate the fry count, then update survival a week or two later, because many newborn fry are eaten and the honest number is the survivors. Record when young males develop their vivid colour and orange-and-black markings, since that is the moment they join the breeding population and start pressing the females. Track the adult sex balance deliberately: too many males for the females means relentless chasing that exhausts them, and your entries should show the ratio drifting before behaviour proves it.
Log every intervention — males moved to a separate tank, fry netted for rehoming, a female isolated to rest — with dates and numbers. Six months of those entries becomes a genuine colony history: which female produces large broods, how fast generations turn over, and when numbers peaked.
Feeding a population that keeps rising
Feeding needs scale with the colony, so log what you offer, how often, and whether fry are finding food small enough to eat. Note whether you crush food for newborns, whether females in late pregnancy feed eagerly or withdraw, and whether algae grazing and plant cover are carrying part of the load for the young. A routine that suited twelve fish may quietly underfeed sixty, and leftovers at the other extreme foul a densely stocked tank quickly — entries on both appetite and leftovers keep you between those failures.
Record condition in the adult females specifically. A female recorded as rounded and active across several broods is coping; one logged thinner after each successive brood, hiding from males between drops, is a candidate for a rest tank, and that decision comes straight from the written sequence.
Using the colony record to plan
The log lets you act early: arrange rehoming when fry counts trend upward, separate sexes before the next generation matures, or add cover when survival entries show fry being picked off. It also protects water quality indirectly, because a counted colony is fed and maintained for its real size rather than its remembered size.
Consult an aquatic veterinarian or fish health professional if you record widespread loss of condition, many fish at the surface, or deaths across age groups — in a dense colony, a written timeline of numbers helps separate a water problem from a breeding-pressure problem.
A monthly census habit
Do a rough headcount monthly, note broods and sex balance weekly during active breeding, and add a feeding line whenever you change the routine. Short entries, kept on schedule, match how this fish actually multiplies.
That schedule lives well in KinsLe's Pet Passport, where your Endler's livebearers' brood dates, colony counts, and separation notes form one packet that keeps pace with a population always in motion.