RobRocksFishTank
Moved On
In light of the unusually high temperatures in the UK, there are a number of threads asking about cooling fish tanks. Instead of responding to every one, I've decided to start one with my advice about the topic because, some people here are a bit sensitive and get offended by my direct approach.
I've lived in southern New England, US all my life and we deal with heat waves almost every year. Around here a heat wave is defined as three or more days in a row with a high temperature of 90 degrees F (32.2C). Every tank I've had has survived a number of heat waves despite not having air conditioning (AC) for most of them. I've been in the top floor of a few apartments for some of those. As I was growing up, AC was a luxury we could not afford and my mother knew how to keep a place cool without it. Her place felt like it had AC. Simple things like blocking as much sunlight as possible with the use of blackout curtains and shades and keeping exterior doors closed can do wonders. Also, taking advantage of cooler PM temps to remove as much excess heat as possible was key. In fact, as I am typing this, I'm having trouble resisting the urge to turn on my lights because I have all the curtains and shades drawn in the middle of the afternoon.
I think most of us will agree that most healthy tanks and fish can take three or more days of higher than recommended temperatures. Even cold water systems. The exceptions being sick fish, reef tanks, tanks and some more sensitive species. The smart recommendation around here is not to directly cool the water but to cool the room. If the water gets a bit warm the temperature swings are less dramatic and it is usually easier than trying to cool the water directly. The only tanks I've seen utilizing chillers to cool the water are reef tanks and other extremely high end saltwater tanks. In fact, more fish are killed by unnecessarily trying to cool water in a way that is hard to control than are killed by the excess heat. The use of electric coolers is a way to cool the water in a controlled fashion and they are used for those high end tanks, but their use is self contradicting for the average hobbyist because the unit is usually in the same space as the tank. They work by removing heat from the water. Guess where that heat goes. Right back into the room plus some more that for the work the unit is doing in order to function, making it even warmer in that room. In turn, rewarming the tank and making the cooler work that much harder. That's why cooling the room is the smart move and is often cheaper.
Another thing to consider is that the warmer the water is, the less capable it is to contain dissolved oxygen. That is why fish hang out near the top when the water is warm. The water at the lower levels does not have enough oxygen. It's not because they cannot handle the temperature. The carbon dioxide/oxygen exchange happens at the surface. A very good way to alleviate hovering at the surface is to increase water circulation. Increasing circulation gets more water to the surface, faster. As long as they are not bouncing off the walls or ornamentation, even fish that prefer slower moving waters will benefit from increased circulation in higher than normal temperatures. I prefer to increase filtration instead of just adding water movers like airstones, powerheads, and wavemakers. My philosophy is: If you are going to move the water, why not filter it? Just put a sponge on it. (I love sponge filters.)
Hope that helps. Good day and good fish. This is Rob, signing off.
I've lived in southern New England, US all my life and we deal with heat waves almost every year. Around here a heat wave is defined as three or more days in a row with a high temperature of 90 degrees F (32.2C). Every tank I've had has survived a number of heat waves despite not having air conditioning (AC) for most of them. I've been in the top floor of a few apartments for some of those. As I was growing up, AC was a luxury we could not afford and my mother knew how to keep a place cool without it. Her place felt like it had AC. Simple things like blocking as much sunlight as possible with the use of blackout curtains and shades and keeping exterior doors closed can do wonders. Also, taking advantage of cooler PM temps to remove as much excess heat as possible was key. In fact, as I am typing this, I'm having trouble resisting the urge to turn on my lights because I have all the curtains and shades drawn in the middle of the afternoon.
I think most of us will agree that most healthy tanks and fish can take three or more days of higher than recommended temperatures. Even cold water systems. The exceptions being sick fish, reef tanks, tanks and some more sensitive species. The smart recommendation around here is not to directly cool the water but to cool the room. If the water gets a bit warm the temperature swings are less dramatic and it is usually easier than trying to cool the water directly. The only tanks I've seen utilizing chillers to cool the water are reef tanks and other extremely high end saltwater tanks. In fact, more fish are killed by unnecessarily trying to cool water in a way that is hard to control than are killed by the excess heat. The use of electric coolers is a way to cool the water in a controlled fashion and they are used for those high end tanks, but their use is self contradicting for the average hobbyist because the unit is usually in the same space as the tank. They work by removing heat from the water. Guess where that heat goes. Right back into the room plus some more that for the work the unit is doing in order to function, making it even warmer in that room. In turn, rewarming the tank and making the cooler work that much harder. That's why cooling the room is the smart move and is often cheaper.
Another thing to consider is that the warmer the water is, the less capable it is to contain dissolved oxygen. That is why fish hang out near the top when the water is warm. The water at the lower levels does not have enough oxygen. It's not because they cannot handle the temperature. The carbon dioxide/oxygen exchange happens at the surface. A very good way to alleviate hovering at the surface is to increase water circulation. Increasing circulation gets more water to the surface, faster. As long as they are not bouncing off the walls or ornamentation, even fish that prefer slower moving waters will benefit from increased circulation in higher than normal temperatures. I prefer to increase filtration instead of just adding water movers like airstones, powerheads, and wavemakers. My philosophy is: If you are going to move the water, why not filter it? Just put a sponge on it. (I love sponge filters.)
Hope that helps. Good day and good fish. This is Rob, signing off.
