Summer Heat Prevention Guide | How to Protect Living Organisms and Plants from Extreme Heat

Summer heat poses a significant risk to both organisms you are breeding and plants you are cultivating. Japan's summer in particular is hot and humid, making it a season prone to various problems such as oxygen depletion from water temperature rise, heat stroke, and root rot from excessive moisture. This article explains measures to protect your precious organisms and plants from summer heat.

Water Temperature Rise Prevention

In aquarium keeping, water temperature rise during summer is one of the most serious problems.

Risks of Water Temperature Rise

• As water temperature rises, dissolved oxygen levels decrease, causing organisms to suffocate from lack of oxygen
• High water temperature affects bacterial activity, making water quality prone to sudden changes
• The ideal temperature for many tropical fish is 24–28°C, and exceeding 30°C is dangerous
• Shrimp are particularly susceptible to high water temperatures, and the risk of death increases above 28°C

Specific Countermeasures

• Cooling fan installation: Directing air across the water surface can lower water temperature by approximately 2–4°C through evaporative cooling
• Introduction of an aquarium chiller: Reliably controls water temperature, but is expensive
• Enhanced aeration: Increases dissolved oxygen levels to prevent oxygen depletion
• Reduce lighting duration: Heat from lighting also contributes to water temperature rise
• Cool the entire room with air conditioning: This method is efficient when you have multiple aquariums

How to Choose Cooling Fans and Chillers

Summer cooling equipment is important equipment that protects the lives of organisms.

Cooling Fans

• Advantages: Inexpensive (around several thousand yen), easy to install, low electricity costs
• Disadvantages: Since it relies on evaporative cooling, effectiveness decreases at high humidity, and water evaporation accelerates
• Selection tips: Choose one with airflow suited to your aquarium size, and verify quiet operation
• Caution: Water evaporation becomes intense, so frequent water top-offs are necessary

Aquarium Chillers

• Advantages: Reliably cools to the set temperature, unaffected by humidity
• Disadvantages: Expensive (tens of thousands of yen and up), generates waste heat that raises room temperature, produces operational noise
• Selection tips: Choose specifications with adequate capacity for your aquarium's water volume
• Installation location: Place it in a well-ventilated area where waste heat can escape

Shading Measures

Intense summer sunlight causes water temperature rise and damage to plants.

Shading for Aquariums

• If your aquarium is placed near a window, block direct sunlight with blinds or shade curtains
• Pasting aluminum sheets on the back or sides of the aquarium for insulation is also effective
• For outdoor biotopes or killifish bowls, block afternoon sunlight with blinds or reed screens

Shading for Plants

• Use shade nets (with approximately 30–50% shade rate) to soften intense light
• Move potted plants to partial shade where they receive sunlight only in the morning
• If signs of leaf scorch appear (leaves turn pale or brown), immediately increase shading
• Be careful as succulents and cacti can also be scorched by direct summer sunlight

Water Quality Deterioration Prevention

Water quality deteriorates at a significantly faster rate during summer.

Causes of Water Quality Deterioration

• High water temperature disrupts the activity balance of bacteria
• Decomposition of leftover food and waste accelerates, causing rapid increases in ammonia and nitrite
• Water evaporation reduces water volume, concentrating pollutants

Countermeasures

• Increase the frequency of water changes (from once a week to twice a week, for example)
• Keep each water change to about one-third of the total volume to avoid sudden water quality changes
• Reduce feed amount slightly (organism's digestive capacity also decreases at high water temperatures)
• Clean the filter frequently (however, only lightly rinse filter media with aquarium water)
• Dechlorinate water for water changes, adjust its temperature to match the aquarium, then add it

Emergency Measures for Power Outages and Extended Absences

Consider countermeasures for summer power outages and extended absences.

Power Outage Measures

• Keep a battery-powered air pump on hand (minimum measure to prevent oxygen depletion)
• Wrap ice packs in a towel and place them beside the aquarium (be careful to avoid sudden water temperature drops)
• Consider installing a UPS (uninterruptible power supply)

Measures for Extended Absences

• Use an automatic feeder
• If water top-offs are needed, install an automatic water top-off system
• If leaving air conditioning running, verify timer settings and temperature settings
• Ideally, you can ask a trusted person to manage the aquarium

Get Through Summer Breeding with BreederDirect

BreederDirect offers abundant information about cooling equipment and management supplies needed for summer breeding. You can also receive breeding advice directly from experienced breeders, so if you have concerns about summer heat prevention measures, please consult with a breeder.

Common Mistakes and Their Solutions

Summer mistakes often occur from overlooking the "side effects of countermeasures" rather than the measures themselves.

Mistake 1: Neglecting water level drops caused by cooling fans While evaporative cooling lowers water temperature, evaporation also lowers water level. In saltwater, specific gravity increases; in freshwater, dissolved substances concentrate. Top off with fresh water and check water level daily.

Mistake 2: Sealing the room when away Even if you only cool the aquarium, if room temperature rises, machine waste heat becomes trapped. Blocking direct sunlight with curtains and circulating air with a fan can still change peak water temperature.

Mistake 3: Overcooling and creating large daily temperature swings If the temperature drops too much at night, the daily temperature variation becomes large, which can actually cause health problems. Set a target water temperature, use a thermostat to manage the lower limit, and keep temperature fluctuations within 2°C for safety.