Last Updated on September 3, 2021 by Marco C.
How to cool down a fish tank in summer can be done by preventing heat from entering your system or the release of heat through evaporation. Heat stress is a limiting factor for both plant and fish growth. If the temperature is too high in your fish tank and in your overall aquaponics system, it will directly affect your fish health and also affect the growth of your plants. Naturally, water has a high heat-carrying capacity which is a measure of how much energy is needed to raise the temperature of the water. This property allows water to stay cooler than atmospheric temperature, especially during hot seasons. Despite this, you would notice that water pipes exposed to the sun would also contain hot water. We will be discussing ways on how to lower your fish tank temperature and keep your aquaponics system cool even during hot summer.
Simple Methods On How To Cool Down A Fish Tank In Summer
Cooldown Your Fish Tank By Keeping Your Pipes Underground
If your fish tank temperature is too high, direct exposure of your components and pipes to sunlight could be the major source of heat for your system. Solid materials and surfaces will heat up slowly but will also store heat longer. As the container or pipe holding the water heats up, it will transfer the heat to the water. This will raise the overall temperature of your aquaponics system. Simply keeping your pipes and surfaces out of direct sunlight will help avoid raising your fish tank and overall aquaponics system temperature too high.
Another way to lower the temperature of your water is to bury your pipes. This will avoid direct sunlight from heating your pipe. As soil temperature is more constant than the air temperature, having your pipes underground will also reduce temperature variations in your water.
Water temperature also varies depending on depth, though in small artificial ponds this difference could be small. I artificially replicate this depth by partially burying a pipe vertically and using an airlift to pump the water from the deepest part of the pipe back up to the aquaponics system. The cooling effect from this may vary depending on the depth of your pipe, soil composition, and atmospheric temperature. Clay soil will take longer to warm up compared to sandy soil. The deeper you place your pipes, the cooler your pipes will be, which will also cool your water.
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Using Heat-Insulating and Reflective Materials For Components Lower Your Fish Tank Temperature
Radiant barriers reduce the amount of heat your surfaces and materials absorb by reflecting heat radiation. These include any reflective surfaces that light could bounce off of like reflective film, aluminum foil, or even styrofoam.
As your hydroponics and growing units require sunlight, they will eventually absorb heat. Covering up the surfaces exposed to the sun using heat-insulating and reflective materials like reflective foam, Styrofoam, or even reflective tape will reduce the heat from solar radiation.
Materials of the color white or painted white also reduce the heat as white reflects all colors of the visible spectrum. Painting the surfaces of your system white will also help reflect heat away from your system.
Materials could also differ in heat conductivity, or the capacity of heat to be transferred. The less heat-conductive the material is, they become more insulating to heat. Examples of mediums that are good insulators are water, air, styrofoam, polystyrene, and reflective foam. Generally, materials with air bubbles trapped inside are good insulators as well as heat does not pass through the air efficiently.
There are also multiple ways of insulating heat from your water;
Components that get direct sunlight could have an external container whose surface is exposed and an internal container that holds the water. This will reduce the heat transferred from the external surface to the water.
For raft type and shallow or deep water cultures, I would suggest the use of styrofoam with holes for your plant cups. Styrofoam is both reflective and a good insulator for heat. Personally, I follow Dr. Kratky’s method of shallow water culture wherein I leave a space in between the styrofoam and the water surface.
Aeration, Circulation, and Evaporation Keep Fish Tank Cool
Aeration is commonly used to supply dissolved oxygen for your fish and plant roots. This can be achieved by the use of air stones or increasing the contact of water surfaces to the air. This exposure to air could also reduce the heat in your water.
As water is exposed to air, this promotes the evaporation of water molecules that contain the most energy. Through evaporation, the heat dissipates from the aquaponics water and subsequently reduces the overall water temperature.
There are different simple ways to aerate your water and reduce your temperature in the process;
Creating a sprinkler effect by drilling holes in your pipes that recirculate to your fish tank or to your hydroponics unit. This creates small and steady streams that have greater surface area for water molecules to evaporate and take the heat with them. This also improves the dissolved oxygen in your water allowing for your fish and plants to thrive more.
Using air stones is good for both your plants and your fishes. Air stones use ambient air and pump it to the water by small holes, creating small air bubbles. As the air bubbles go up, it agitates the water surface and increases surface area for evaporation to occur. Make sure that the air pump is not exposed to the sun. If the pump heats up, this will pump hot air into the water subsequently increasing temperature instead.
How To Lower Fish Tank Temperature- Conclusion
Depending on your location and what you are growing, the ideal temperature for your system will vary. Heat stress could still happen anywhere especially if the whole system is exposed to the sun. You will be able to enjoy better yields for your plants and fishes even during hot summers. Avoiding direct sunlight on components will help you avoid raising your water temperature too high. Simple design considerations such as what materials to use and having proper aeration for your water will also help reduce temperature. Water is a self-regulating medium as well as a good heat sink, by taking advantage of the properties of water, you could cool your system in multiple ways.