Create one album per fish, and give each album the same four parts: a clear photograph of the left side, a clear photograph of the right side, a close-up of any distinctive markings, and a dated note recording the fish's size. Photograph every fish against the same plain background, name each file with the fish's name and the date, and store the albums in one backed-up folder. This record works because patterns differ. On koi, cichlids and fancy goldfish, the arrangement of colour patches, fin shape and body markings identifies an individual far more reliably than size or general colour alone.
Taking the Two Side Photographs
Photograph each side separately, with the fish side-on to the glass and the whole body in frame from mouth to tail tip. A container with clear sides, filled with tank water, gives a cleaner shot than chasing the fish around the main tank, and it keeps the fish calm and wet throughout. Turn lights up, wipe the outside glass, and wait until the fish settles level before you press the shutter. Take several frames of each side and keep the sharpest one, because a blurred fin edge can hide the very notch or split that sets this fish apart. Both side photographs belong in every album, even when one side looks plain: a plain left side is itself identifying when another fish carries a mark there.
The Markings Close-Up and the Size Note
Photograph any distinctive marking close enough to show its outline and position: an unusual patch, a bent fin ray, a scar, or an eye difference. Frame the close-up so a known landmark, such as the gill cover or dorsal fin, appears at one edge, which lets anyone place the marking on the body later. Then complete the fourth part, the dated size note. Measure the fish in its clear container against a ruler held outside the glass, and write the length with the date in the album. A size note without a date proves little, because a young fish can change the comparison within months.
Naming, Storing and Refreshing the Albums
Name files so a stranger can follow them: the fish's name, the part, and the date, in that order. Keep the folder of albums with your other household records and keep a second copy in a separate place, such as cloud storage or a drive kept elsewhere, so one failed phone does not erase the record. Refresh an album when the fish grows noticeably, when its pattern changes, or when a fin injury heals into a new mark. Add the new four parts beside the older set rather than replacing it, because a dispute may concern how the fish looked at an earlier date.
Using the Record When It Matters
Keep the albums retrievable under pressure. If a fish is lost during a house move, sold on, or mixed with a near-identical fish at a show or in a shop tank, open the album for that fish and work through its four parts in order: left side, right side, markings close-up, and dated size note. Show the side photographs first, since they carry the overall pattern, then the close-up to settle the detail, and quote the size note with its date to confirm the fish's growth stage at the time. Keep the naming and storage rules identical for every album, so you never waste the urgent moment decoding your own filing. A record built this way also helps a buyer, a sitter or a vet confirm that the fish in front of them is the individual described, without handling the fish or draining the tank for a closer look.
In KinsLe, Pet Passport filing lets you attach the refreshed set to the same fish profile, keeping older and newer identification photographs together in sequence.