Fish sitting while you're away: feeding, power cuts and heat

Fish are the pet most often left alone for a weekend, and the one where the reasoning is most often wrong. The City of Riverside's utility advice says most aquarium fish can go multiple days without eating, and the RSPCA says underfeeding is safer than overfeeding. So hunger is rarely the danger on a short trip.

The danger is the equipment and the water. A filter that stops, a heater that sticks on, a power cut on a hot afternoon or a fish that dies and rots unseen can turn the water toxic in a day or two. The Merck Veterinary Manual says the warmer water becomes, the less oxygen it holds, and the University of Florida's extension service says fish gasping at the surface are short of oxygen and need emergency aeration. None of that is fixed by leaving extra food, which makes it worse.

That is why the RSPCA's holiday advice is for a responsible person to check the fish and equipment each day, and why it adds that tropical fish need feeding daily. Petym's planning guide follows: a daily visit for any trip longer than a day, with the weekly water change done as normal on trips of a week or more.

The RSPCA does not recommend holiday feeding blocks, because they release a lot of food into the water very quickly. In a warm Indian flat, that food rots, ammonia rises and the water quality drops just as nobody is there to change it.

An automatic feeder releases a measured amount each day, but the RSPCA says it still needs to be checked every day to make sure it is working. Feeders jam, tip their whole load in, or run in a power cut that has also stopped the filter. So an automatic feeder can reduce how often someone feeds the fish, but it does not replace the daily check.

Petym's advice is simpler: put each day's food in a labelled pill box or small packet, one compartment per day, so the sitter feeds exactly what you would. Write how long the fish should take to eat it, and ask the sitter to remove anything left over.

The RSPCA warns that a tank placed by a window can heat up dangerously, and the Merck Veterinary Manual says sunlight warms the water and feeds algae. A shut flat in May, with the curtains open and no fan, is the worst case: the water warms, holds less oxygen, and the fish need more oxygen as they warm up, as the University of Florida's extension service explains. The India Meteorological Department says heat waves come mainly between March and June.

Before you leave, close the curtains in the tank's room and keep the tank away from any spot the afternoon sun reaches. Show the sitter which inverter socket covers the filter and air pump, and leave the battery pump with new batteries next to the tank. If your water runs warm in summer, leave a few ice cube bags in the freezer marked for the tank.

In the monsoon, windows stay shut and mosquito sprays come out. The RSPCA warns that aerosol sprays and cigarette smoke can be toxic to fish, so ask the sitter not to use insect spray or room freshener near the tank and keep the lid on. The Animal Welfare Board of India's 2026 heat circular reminds owners that the person in charge of an animal is responsible for its well-being, which, while you travel, includes the fish.

• Ask the sitter to send a photo of the thermometer with the daily photo update (Petym's advice).
• Leave the light on its timer, not on all day: constant light stresses fish.
• Do not leave a heater set high and hope; a betta's range is 24 to 26 °C.

Before the first booking there is a free meet and greet at your home, so the sitter sees the tank, learns which switch runs what, where the battery pump is and what each fish looks like. You book and pay through Petym, and the sitter is paid after the booking.

During the booking the sitter follows your plan as you wrote it, feeds the meals you measured, logs each visit and sends a photo update every day. If something goes wrong, the sitter calls you first; fish emergencies are mostly about the water, so your instructions matter most. Every Petym sitter has an identity check with PAN and pet first-aid training before the first booking, and a named 24-hour vet within reach.

Petym is not taking bookings yet; it opens city by city once sitters have passed its checks. Its services are built first around dogs and cats, and a tank is often looked after alongside a dog or cat in the same home. At the meet and greet, check that the sitter is comfortable with your equipment and knows the power cut steps on this page.