The arrival entry, written on day one
Every batch of new fish gets its record started the day it arrives, before the bag is even opened. Write the species and how many, the shop, breeder or fellow keeper they came from, and the date they entered quarantine. Note the condition they arrived in — active and coloured up, or clamped and pale from the journey — and the water they travelled in if you test it. This entry is the anchor for everything that follows. Months later, if a question arises about where a fish or a problem came from, the arrival entry answers it from fact instead of from a keeper's fading memory of a busy Saturday at the fish shop.
Daily quarantine observations that actually help
Quarantine earns its keep through observation, so give the record a short line every day or two while the new fish are isolated. Note feeding response first — new fish eating confidently is the single best sign — then anything visible: spots, frayed fins, flicking or rubbing against objects, rapid breathing, a fish hanging apart from its group. Write 'all feeding well, nothing seen' on quiet days rather than leaving blanks, because a written all-clear is evidence while a gap is ambiguous. Log the quarantine tank's water tests on the same page, since a stressed reading in a small bare tank explains behaviour that might otherwise be blamed on disease.
Dates that mark the quarantine honestly
The dates in a quarantine record do three jobs. The start date sets the clock. Any date on which a symptom appeared, or a treatment was given on a vet's or shop's advice, marks the middle honestly — and good practice restarts or extends the isolation from that point rather than the original start. The release date, when the fish finally join the community tank, closes the record. Writing all three prevents the commonest quarantine failure, which is not poor conditions but impatience: releasing fish because they look fine today, without the written trail showing how long they have actually been watched.
The move into the community tank, recorded too
Record how the release was done — the acclimation method used, how long it took, and how the newcomers and residents behaved in the first hours. Note who chased whom and whether everyone fed that evening. If a resident fish falls ill in the following weeks, this entry plus the quarantine page lets you work backwards calmly. Keep the batch's record open a little longer after release, adding a line at a week and a month, so the arrival story ends with the fish established rather than with the door of the quarantine tank closing.
Records that stay with the fish afterwards
A completed quarantine page should not be thrown away once the fish are swimming in the main tank; it becomes part of their permanent history — proof of where they came from, how they were screened and when they joined the community. If the fish are ever rehomed, that page is the most reassuring document a new keeper can receive. KinsLe's Pet Passport keeps new arrivals' records together in one portable packet with the tank's profile, so every fish in the community carries its arrival and quarantine story with it.