Why a guppy diary starts with a headcount
A guppy weekly diary starts with a headcount because a guppy tank changes population faster than almost any other home aquarium. Count adults first, then fry you can see, then note any fish you expected to find and did not. Record females that look heavily gravid, fry that appeared since last week, and any young fish you moved to another tank or rehomed. Without that count, a slow loss of one fish at a time goes unnoticed behind plants, and a sudden fry boom that will overload the filter in a few weeks comes as a surprise instead of a planned adjustment.
Water and feeding lines for a fast-breeding tank
Water notes in a guppy diary should track how the load is changing, not just the numbers on one test. Record temperature, ammonia, nitrite, and nitrate, plus how much water you changed and whether the filter was cleaned. Add what you fed adults and, separately, what you fed fry, because finely crushed food added several times a day fouls a small guppy tank quickly. Note uneaten food sitting on the substrate and whether the surface film thickened, since both hint that feeding has crept ahead of what the current population and filter can handle.
Tails, colour, and the fish that hangs back
Tail condition deserves its own line in a guppy diary because flowing male tails show wear early. Note fraying, clamping, white edges, or a tail that is suddenly shorter, and name which fish by colour or marking so next week you can tell whether it spread. Add a behaviour line for any guppy rocking in place, hiding behind the filter, or sitting apart from the group at feeding time. In a guppy group, the fish that stops competing for food is often the first signal worth acting on, and a dated note separates a one-day sulk after a water change from a fish that has declined across three entries.
Keeping the guppy diary to five minutes
A guppy diary stays sustainable when you write it during the weekly water change with a fixed prompt list taped inside the tank cabinet. Use abbreviations for normal, leave the fry count as an honest estimate rather than chasing every baby through the plants, and add one photo only when a tail, a belly, or a colour change needs comparing later. If you separate males and females or move fry on, log the move on the day it happens inside that week's entry so the population maths still makes sense when you reread it months later.
How long to keep guppy entries and summaries
Guppy breeding and illness notes are worth keeping far longer than routine water lines, because the same fin problems and fry survival patterns tend to recur in fish descended from the same parents. Keep recent months of full entries within reach, condense older routine weeks into test ranges and population totals, but keep any entry covering a disease episode, a tail loss, or a notably successful fry batch in full. That layered record shows whether a problem followed a new fish, a new food, or a crowded tank. Kept in that form, KinsLe lets the Pet Passport carry your guppies' breeding history and health turning points as one continuous record.