Counts first, because a guppy tank changes weekly
A guppy diary earns its keep through counts, because births and growth reshape this livebearer's tank faster than almost any other fish's. Record adult numbers by sex, new fry spotted and roughly how many, and any deaths, so a slow decline is never hidden by a fresh batch of young. Note which females look heavily rounded with a dark area near the tail and which have slimmed after giving birth, since that cycle explains appetite and hiding shifts. Add the male-to-female balance, because too few females for the males present shows up in the diary as constant chasing and worn, tired females.
Tails, colour, and fin detail for guppies
Tail condition deserves its own line in a guppy entry, because the males' large, flowing tails fray, split, and pick up nipping damage before anything else looks wrong. Describe tail edges precisely: clean and full, slightly ragged, clamped tight, or showing pale or reddened margins. Note male colour intensity and whether the whole group looks bright or one fish has gone dull, and check females for a straight spine and full body rather than a pinched, hollow profile. Record shimmying, where a guppy rocks in place instead of swimming, in those exact words, because that one behaviour word tells an adviser a great deal.
Feeding and surface behaviour to log
Feeding notes for a guppy should say whether every fish came up promptly, since guppies feed eagerly at the surface and a no-show is conspicuous. Log the foods offered, including finely crushed options the fry can manage, and whether the smallest young are finding food or being outcompeted along the surface line. Note resting on the substrate, hiding behind the filter, or hanging in a corner away from the group, all unusual for an active guppy. Pair the entry with weekly water test results and temperature, because this species dislikes cold or swinging conditions, and a chilly week often explains a dull, inactive entry better than illness does.
Fry, plants, and tank changes in the diary
A guppy diary should track the nursery side of the tank alongside the adults, since fry survival is a running health indicator. Note cover available, such as floating plants or dense growth, roughly how many fry survive their first days, and whether adults are hunting them relentlessly or the planting is doing its job. Record any fish moved to or from another tank, new arrivals and their source, and equipment changes, because guppy problems frequently follow an introduction by a week or so. Writing the timing down is what lets you connect a later symptom to an earlier change instead of treating it as a mystery.
When guppy notes should prompt prompt advice
Escalate from routine logging when a guppy diary shows shimmying across several fish, rapid breathing, white spots spreading through the group, tails rotting back noticeably, or females wasting despite eating. Test the water, write the results beside the week's symptoms, and seek advice from an aquatic veterinarian or experienced fish keeper with the counts and dates in hand. A single fish isolating and refusing food also deserves same-week action rather than a wait-and-see note. With the running guppy record kept in KinsLe's Pet Passport, you can show exactly when signs began and how the group has changed since.