Put the brackish balance at the top of the brief
Brief a house sitter on emergency care for a bumblebee goby by leading with salinity, because this small brackish fish tolerates many things but not a sudden slide toward fresh water. Leave every container the sitter may use pre-mixed, tested and labelled by you, and mark the tap-water rule in plain words: nothing enters this tank except from those containers. Show them the hydrometer reading you took together and write down the number, so any later check has your baseline beside it rather than a guess.
Show the sitter how these gobies actually live
Understanding the fish comes second in a bumblebee goby briefing, because a sitter who expects normal fish behaviour will misread this one completely. Bumblebee gobies are bottom fish: each perches on the sand or a rock, claims a shell or small cave, and shuffles between territories in short hops rather than swimming. A goby on its rock, bands bright, pectoral fins fanning, is a fish in perfect order. Knowing where the fish should be tells the sitter what wrong looks like when it happens.
Portion tiny bottom foods, nothing else
Feeding a bumblebee goby under a sitter needs portions and a ban list, because the wrong food either never reaches the fish or spoils the sand it lives on. Measure out the thawed tiny foods into daily pots and show the sitter how to distribute them along the bottom near each territory, a little at a time, watching pieces land rather than drift into the filter. Dry food alone is a poor plan for these gobies and uneaten scraps on the substrate foul a small brackish tank quickly.
Define the emergencies in goby terms
Emergency signs in a bumblebee goby are changes of place and colour, so spell them out for the sitter in those terms. A goby that leaves the bottom and hangs in the water column, props itself at the surface or lies on its side on the sand is a fish in trouble and earns an immediate call. Bands fading to grey, fins held clamped, rapid breathing or a goby that stops defending its perch and lets tankmates take its cave all belong on the same call-you list. The sitter's first checks are the ones you taught: is the filter running, does the water match the labelled reading, and has anything unlabelled gone into the tank. Your number, then the aquatic vet's, sit on the card, and any suspect water stays untouched until you have advised, since a hasty change with the wrong mix deepens a brackish crisis.
Rehearse one full visit before you go
Run one complete visit with the sitter before you leave, because a bumblebee goby tank has more labelled containers and quiet rules than most and memory drops half of them. Have the sitter do the water check against your baseline, feed the measured pots along the bottom, point to each goby's perch and say which one owns it. Confirm the daily message you want, including a photograph of the bottom of the tank, where all the real news in this aquarium happens. Agree that equipment noises, leaks or a cloudy tank are reported the hour they are noticed. These gobies are hardy inside their routine and fragile outside it, and a rehearsed sitter keeps them inside it.
Keep the brackish brief in a single handover
The details that keep a bumblebee goby safe are exactly the ones a sitter forgets separately, so the salinity rule, the container labels, the bottom feeding and the call signs belong in one document they open at the tank. Filed on KinsLe under a Care Pass, the labelled-container system and perch-by-perch feeding plan stay readable at the glass, long after your spoken walkthrough fades.