Aquarium summer heat planner for India

Result

At 34.7 °C (94 °F), 3 of your fish would be above their range. Start the steps below now.

• Zebra danio18–26 °CAbove its range
• Bronze corydoras22–27 °CAbove its range
• Guppy22–28 °CAbove its range

Shared range

22–26 °C (72–79 °F)

Aim for

24 °C (75 °F)

What to do, most important first

1. Add surface movement. Point the filter outlet at the surface, or run an air pump and airstone. Warm water holds less oxygen: about 7.83 mg/L at 28 °C against 7.30 mg/L at 32 °C (USGS).
2. Shade the tank. Close curtains or blinds, or move it away from a sunny window. Direct sun heats the water and feeds algae.
3. Switch the light off in the hottest hours, or halve the light period. JBL puts halving the lighting time at about 1 °C. Live plants still need several hours of light a day.
4. Open or remove the lid. Evaporation carries heat away, about 1–2 °C by JBL's figures. Many fish jump, so leave a gap or fit a mesh cover.
5. Add a fan across the water surface. It is the cheapest cooler: JBL puts purpose-made aquarium cooling fans at 2–4 °C, less in humid air. JBL warns that ordinary computer fans are unsafe near water.
6. Read the thermometer morning and evening. In a study of Chennai homes, rooms peaked around 8–9 pm. If fish gasp at the surface or crowd the filter outflow, test ammonia and nitrite and add more aeration.
7. Feed a little less. Digestion uses oxygen, and uneaten food fouls warm water quickly.
8. Top up evaporated water every day with dechlorinated water. Evaporation leaves minerals behind, so top-ups don't replace your weekly water changes.
9. Cool it slowly and skip ice. JBL warns that ice, cooling packs and cold water changes drop the temperature fast but only briefly, which stresses fish. The University of Florida's extension vet suggests about 0.5–1 °C every few hours.
10. Keep a battery or USB air pump ready for cuts of 2 hours: charged, with airline and an airstone, and tried once a month. Oxygen runs short first when the power goes. Size the backup as watts × hours: a 5 W pump for 2 hours needs about 10 Wh.
11. Don't feed while the power is off. Fishkeeper warns that extra waste adds ammonia with no filter to remove it.
12. In a summer cut, take the lid off and run a battery fan across the surface if you have one (University of Florida).
13. Protect the filter bacteria. They start to die after about an hour with no flow, so test ammonia and nitrite for a few days after a cut and change some water if either reads above 0 ppm.
14. Follow the aquarium power cut plan for what to do before, during and after a cut.
15. If the free steps aren't enough, the lasting answers are a cooler room, a chiller, or fish whose range reaches higher: see fish that tolerate warm water and best aquarium fish for Indian weather.
16. A heater can only add heat. In a hot room it does nothing, so you can unplug it for the hot months. Plug it back in before winter.