Tank temperature increases and how to handle them

[Byron]

This article is in the current PFK and covers the handling of tank water increases during heat waves. I've said most of this myself, but it bears repeating as some still ignore the advice not to use ice/cold water, etc. It applies to fresh and marine tanks.

How to stop a tank from overheating

One of our readers asks expert Jeremy Gay how to avoid his reef tank heater from overheating the water...

www.practicalfishkeeping.co.uk

 

[JuiceBox52]

Thank you Byron!!

 

[Sgooosh]

i saw some "tank coolers" in the pet store, do those work?

 

[Colin_T]

The tank coolers that are small fans that blow air over the top of the tank only reduce the temperature by 1 or 2C. A normal fan that you would use to cool yourself down with, is cheap and does the same job.

You can buy aquarium chiller units that are refrigerated units connected to the aquarium by hoses. Water is pumped from the aquarium, through the chiller unit and back into the tank. It is cooled in the chiller unit.

Aquarium chillers are expensive and normally keep the water too cold for tropical fish. However, some are better than others and can cover a wider range of temperatures.

The best value for money is a portable room air conditioner that keeps the aquarium and you and your family cool. Portable room air conditioners cost about the same or sometimes less than an aquarium chiller unit and cool the tank and entire room down. An aquarium chiller unit only does the fish tank.

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In Australia, we try to have air conditioning on newer houses but not all have them. Reverse cycle air conditioners are common now because they warm in winter and cool in summer. Most of our houses are poorly insulated even though there are building codes saying all new houses must have some roof insulation. My place is 3 years old and doesn't so developers and home owners are breaking laws. Most houses here don't have double glazed windows either and virtually none have wall insulation or floor insulation.

In the UK and most of the cooler parts of Europe and America, houses have very good insulation and if you can cool the house down, the insulation should help keep it cool and stop the air temperature and aquarium water temperature from getting too high.

A portable room air conditioner (either a standard refrigerated unit or a reverse cycle type or an evaporative cooler) would all help cool the inside of your place down and help keep the tank cooler.

 

[itiwhetu]

Test your tap water temperature, and then just do water changes using that.

 

[Colin_T]

Test your tap water temperature, and then just do water changes using that.

We don't even bother trying to drop the tank's water temperature here. We just let the fish live in 30C+ water during summer and they are fine. Some corals have an issue above 28C but the fish adapt and don't have any problems with the warmer water as long as there is plenty of oxygen.

 

[raylove]

Yeah, even my cooler water fish such as denisoni barbs seem to do fine for short periods of heat in the summer. Last week their tank was 31.5C and they were acting completely normal.
I wedge the covers open slightly to allow heat to escape but I don't turn the lights off. Surely that would stop the plants growing and reduce oxygen just when you want to maximize oxygenation?
In such hot weather I don't heat water when changing - I take it straight from the tap (with conditioner of course). A 10% change using the cooler water lowered the overall tank temperature by about 0.5C, so nothing dramatic but worth doing. I leave a circulating pump running so the cold water gets mixed in very quickly so the fish are unfazed should they swim into a cold current!

 

[Rebecca999]

Hi Colin,
I'm in QLD and have come home to a 30 plus deg tank with the heater off, have guppies, endlers and an albino cory, based on your WA experience do you think this is problematic or okay if I’m running an airstone and have plenty of surface agitation? Should I keep the lights off when it’s hot? Thanks in advance.

We don't even bother trying to drop the tank's water temperature here. We just let the fish live in 30C+ water during summer and they are fine. Some corals have an issue above 28C but the fish adapt and don't have any problems with the warmer water as long as there is plenty of oxygen.

 

[Colin_T]

Hi Colin,
I'm in QLD and have come home to a 30 plus deg tank with the heater off, have guppies, endlers and an albino cory, based on your WA experience do you think this is problematic or okay if I’m running an airstone and have plenty of surface agitation? Should I keep the lights off when it’s hot? Thanks in advance.

As long as you have plenty of aeration/ surface turbulence the fish will be fine.

If you have live plants in the tank, leave the light on during the day or whenever you normally have it on.

If the light unit is sitting on the coverglass or very close to the top of the aquarium, raise it up a few inches so there's more airflow around the light unit. This will reduce the heat from the light warming the water.

 

[GaryE]

In Australia, do you turn the heater off in summer as most of us do in Canada? I used to find that if I left heaters on, when the temperatures did get decent again, they would often malfunction, either not coming on or sticking and killing fish.

 

[Colin_T]

In Australia, do you turn the heater off in summer as most of us do in Canada? I used to find that if I left heaters on, when the temperatures did get decent again, they would often malfunction, either not coming on or sticking and killing fish.

I turned my heaters off as soon as the daytime temperatures were around 22-24C and left them off until the weather got cold enough to drop the tank temps overnight.

If you are further north in Queensland or northern New South Wales, or anywhere in the top half of the country you don't need heaters at all.

 

[Rebecca999]

As long as you have plenty of aeration/ surface turbulence the fish will be fine.

If you have live plants in the tank, leave the light on during the day or whenever you normally have it on.

If the light unit is sitting on the coverglass or very close to the top of the aquarium, raise it up a few inches so there's more airflow around the light unit. This will reduce the heat from the light warming the water.

Great, thank you! Will shift the heater up a little today.

 

[Colin_T]

Great, thank you! Will shift the heater up a little today.

What do you mean by shift the heater up?

You don't need the heater on at all and I would turn it off, let it cool down for 15 minutes, remove it from the aquarium, rinse it off and pack it away.

 

[Rebecca999]

What do you mean by shift the heater up?

You don't need the heater on at all and I would turn it off, let it cool down for 15 minutes, remove it from the aquarium, rinse it off and pack it away.

Sorry my brain was uncaffeinated, meant the light. All good today, 27-28 deg.