# Water temperature problem



## ccla (Feb 2, 2009)

So I am all done and cycling my 75g and I think I overlooked a problem with the setup. Since the tank is on the second floor, it gets really hot up there during the day. I have two computer fans in the hood to circulate the air and I leave the glass tank top open. However, the water temperature has reached 87F.
I was thinking of putting a fan in the hallway to circulate the hot air (the AC is on downstairs during the day) but I was wondering what would be the highest temperature should I feel comfortable with.
I while I thought I was reading a thread with people keeping two different sets of temperatures (one in the winter and one in the summer) but I cannot seem to find it now!


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## SoDakJeep (Mar 21, 2009)

if you have a heater maybe check that 1st and set it lower or as low as it can go. I don't know what to tell you though as I have never dealt with the problem. Others will be along shortly to help you though.

Wow if your water got that hot man I would not want to be in your house. It must be almost 90 deg. upstairs. I would suggest a fan and open the tops if possible.


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## vaypourus (May 20, 2008)

I hate to say it, but you really only have two good options if you air temp is getting that high.

1. Air Conditioner for the room.

2. Chiller for the tank.

Your africans really should stay in the 74-78 *f range as Lake Tang stays about 78 *F year round day and night. You can bring it up higher and the safe zone seems to end around 85 degrees. A fan solution may drop your temp a few degrees, however any temp fluctuations above that temp can be dangerous to fish. Water also becomes less oxygenated at higher temps, and I've experienced poorer color, lethargic activity, and overall signs of fish stress years ago when my temps hit the 80's for extended periods of time.


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## lloyd (Aug 24, 2005)

i keep 1/2 my tanks in the garage, and with our present heat wave (yes...we have heat waves in Canada :wink, those tanks are presently at 86-88. although i blame the heat for stalling some species reproduction interests during mid summer (in particular, my cyphotilapia collection), i have never considered the situation to have caused a death. i increase water change volumes, add a few power heads (my stingrays really like the venturi option during heat waves) and feed less during these times. HTH.


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## ccla (Feb 2, 2009)

The funny thing is that the upstairs is not even that hot. Today as I got home, the tank was at 87F while the air temperature was 83F! I guess all of the filters and pumps add to the temperature.
I was afraid that the answer was going to be a chiller. This weekend I am going to play around with dropping a frozen bottle of water behing the background to see how long it takes to melt and what happens to the temp. I am afraid it will not do much and may not last too long.
My power-head has a venturi option, so the oxigenation should not be a problem but I still worried about the high temperature.


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## ccla (Feb 2, 2009)

P.S.

Anybody got a suggestion for a good chiller for a 75G tank that will not cost me an arm and a leg?


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## vaypourus (May 20, 2008)

ccla said:


> Today as I got home, the tank was at 87F while the air temperature was 83F! I guess all of the filters and pumps add to the temperature.


I've found that even really good heaters will maintain a constant temp...until the room temp starts to climb. I don't really understand it, but in the summer I find myself dropping my heaters down a couple degrees to keep my tanks from hitting that 80* mark.

An efficient window mount air conditioner should be inexpensive...at least 1/3 to 1/2 the price of a small chiller. I run a 6000 BTU Samsung AC unit that cost me less than $150. On energy saver mode in my house (living room, dining room and my bedroom) and it keeps the temp in the low 70's and doesn't jack up our energy bill (I think I saw about a $10/month increase over spring and fall energy costs). If you have that ability, I would think that would be your best option.


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## ccla (Feb 2, 2009)

vaypourus said:


> I've found that even really good heaters will maintain a constant temp...until the room temp starts to climb. I don't really understand it, but in the summer I find myself dropping my heaters down a couple degrees to keep my tanks from hitting that 80* mark.


Thanks vaypourus,

I will try and see if by dropping the heater the wwater temperature will fall. THis morning before I left I opened the top of the canopy to see if perhaps it needs more air circulation.


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## Dj823cichild (Mar 30, 2009)

I'm having the same problem as you ccla. But I already have 12,000 btu ac window unit ready. I've been keeping an eye on my water temps in my 60 gallon african tank and my max temp was 82. I know the average and comfortable temps is 76 to 82. I'm going to turn on my ac on low and see what happens and how it will cool my tank. I would suggest a inexpensive ac unit rather then a chiller. Good luck my fellow neighbor :thumb:


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## ccla (Feb 2, 2009)

Well I think the first thing that I need to do is put some additional holes in the canopy. I left the canopy open since this morning, and the temperature in the tank has dropped to 85.7F.
Maybe I can drill some holes on opposite sides and then attach fans to move air across the surface of the water.
I will still test how long a frozen soda bottle will last and what drop in temperature it will cause this weekend.


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## under_control (Jan 9, 2008)

Quit running lights. Add an air pump. remove the glass tops completely.


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## Dj823cichild (Mar 30, 2009)

I just did the ac test today and it worked perfect ccla, I'm telling you it's your best bet. But it's only my opinion. I ran my ac on low today here in my den from 11am to 5pm and the water temperature was at 76% as you know we had temps were close to 90 today. Keep us posted, I really don't think the frozen water bottle will work for the whole day.


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## ccla (Feb 2, 2009)

So I gave up on the ice bottle idea. Instead I bought a small fan that can fit hanging on the canopy and blows across the surface of the water (unfortunately the canopy has to be open in order for the fan to work). In just a couple of hours this afternoon the water temperature has dropped all the way down to 81.5F.
I now am testing how much the temperature will raise while I leave the lights on (I am hoping it does not go up more that 1 degree or so. I will leave the lights on in the tank from 4pm to 11pm.
We'll see what happens.


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## Sean117Ply (Oct 18, 2006)

lloyd said:


> (yes...we have heat waves in Canada :wink


Yeah 30c is rather warm, especially when you get 2 a year 

Yeah you may need a chiller or AC in the room.


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## Dj823cichild (Mar 30, 2009)

Keep us posted Ccla. I did try the ice block in the tank on sunday with some water conditioner of course and it dropped my tank like 3 degrees but after like 2 hours it went back up and I put on my ac here in the den.


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## klc9100 (Apr 14, 2009)

my son's bedroom is upstairs and even with the ac on, it gets pretty warm up there during the day (summer time in georgia is terrible). he has a tank in his room that gets hot like that too. i have found that leaving the top open and leaving the ceiling fan on really helps.


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## vaypourus (May 20, 2008)

I am not an engineer anymore, so somebody might want to double check my calculations.

1 calorie = amount of energy required to increase/decrease the temperature of 1 kilogram of water by 1 degree Celsius.

A gallon of water weighs 8.35 pounds = 3.79 kilograms. So 75 gallons = 284.25 kg of water.

There are 4.18400 joules in 1 calorie. So, this means that to cool 284.25 kg of water 1 degree, you would have to remove 1189.30 joules of energy to drop the temp in your tank 1 degree C.

340,000 joules is required to melt one kg of ice. So, if we are removing 1189.30 joules of heat through the melting of ice, .0035 kg would be required to do so. .0035 kg = 1.23 ounces, which is roughly the weight of 2 medium sized ice cubes.

Also, keep in mind that we are talking in *C here. 1 *C = 1.8*F. So, in melting 2 ice cubes in a 75 gallon tank you would see a decrease in temperature of about 1.8*F.

Now, before you say "that doesn't seem right" consider that this is assuming the water is not picking up any heat from the surrounding air or equipment. Additionally, because ice floats, much of the heat involved in melting the ice would come from the air right above the water. To get this to work correctly, you would have to submerse the ice completely.

Due to the relatively poor thermal conductivity of soda lime float glass (usually in the range of .95 to 1.05, compared to wood or fiber insulation, which is roughly .04 to .045) and the large surface area of the glass (on just the sides alone, we have 2772 sq inches of surface area. The bottom will be excluded, due to several inches of silica sand, I am not aware of whether there are glass tops on the tank or not, which would also make a difference), you are gaining this heat back almost as quickly as the heat would be removed in melting the ice. So, in real life, you would have to add 3-4 ice cubes to see a drop of temperature of about 1.8 *F. Again however, by the time the temperature change had dispersed though the tank, it would most likely have gain most of it back from the glass sides of the tank.

Increasing airflow over the top of the tank to increase evaporation is a smarter idea. It takes 540 calories/g to evaporate water. This means that 540 calories would have to be put into a gram of water to turn it into gaseous water vapor, or 2259.36 joules would be removed from your tank in evaporating 1 gram of water. So for every gram of water evaporated, you would see a decrease in temperature of 2 *C. Hot water evaporates quicker than cold water, and a fan placed over the top of water will increase evaporation as well.

In short, using a fan to blow air over the top of the tank will draw more heat from the tank than constantly adding ice cubes to it.

I imagine that a simple closed loop radiator system with a fan would drop the temperature of the tank immensely. A motorcycle radiator with small 12 volt fan and a Danner md5 mag pump could be slapped together for about $150, and I'd be willing to bet the results would be pleasing and still considerably cheaper than even a low end chiller.

*note....I have simplified many aspects of this here to get the point across. I have rounded all numbers to 2 place values for simplification, ignored the effect of different temperatures on constants, etc. Taking all of the things I ignored into effect would take a lot of time and produce slightly different calculations, but I think it would be pretty close to what you see here. Either way, I hope you get the point.


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## Dj823cichild (Mar 30, 2009)

Wow that's a lot of facts and figures and with all that wisdom and knowledge I wouldn't doubt you for a second! :thumb: Maybe one of these days I'll try getting a fan and see how it works over my tank.


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## ccla (Feb 2, 2009)

Tonight I found that the temperature of the tank is 79.7F whereas the room temperature upstairs is 85F! I might not have to buy a chiller!


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## Dj823cichild (Mar 30, 2009)

So what are you doing to get it there? I know we live kind of close well in neighboring states. It was like 86 here in Philly Pa today and I didn't use an ac at all I kept the top of my tank covers open and I came home to check and my temp was 78 %. Please share your technique Ccla.


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## ben1988 (May 2, 2009)

please do since my tanks are at 85 and have not been lower for a week now


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## Dj823cichild (Mar 30, 2009)

Ouch Ben! Have you tried installing a window unit if you tank is in a enclosed room like a den or a bedroom? I have a 12,000 btu here in my den but I haven't used it in the last 2 days and I've been fine.


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## ccla (Feb 2, 2009)

ccla said:


> So I gave up on the ice bottle idea. Instead I bought a small fan that can fit hanging on the canopy and blows across the surface of the water (unfortunately the canopy has to be open in order for the fan to work). In just a couple of hours this afternoon the water temperature has dropped all the way down to 81.5F.
> I now am testing how much the temperature will raise while I leave the lights on (I am hoping it does not go up more that 1 degree or so. I will leave the lights on in the tank from 4pm to 11pm.
> We'll see what happens.


This is all I did. I opened the canopy six inches or so and put a six inch fan blowing on the surface of the water 24 hours per day. Nothing else. Tonight the temperature of the tank was 80.1F and the air temperature was 85F again.
I will keep track of the temperature as the tank finoshes cycling to make sure that the temperature does not go too high.


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## Dj823cichild (Mar 30, 2009)

Did you buy the 6 inch fan at your LFS or somewhere else? I'm happy you are making out well


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## ccla (Feb 2, 2009)

Dj823cichild said:


> Did you buy the 6 inch fan at your LFS or somewhere else? I'm happy you are making out well


I bought it at Wal Mart for $7.


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## Dj823cichild (Mar 30, 2009)

Sweet is it one of those clip on desk fans?


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## ccla (Feb 2, 2009)

No it is a fan that sits on a wire stand. Here is a picture of the fan:










The reason I ended up not getting the clip on is that I would have had to keep the canopy open a lot more and I need it to be as low as possible so that the light from the canopy is not too high above the tank. I made a shelf that hangs from the side of the canopy to hold the fan. I also cut some egg crate to size to cover the open tank top so that if the fan falls it will not fall in the water.


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## ccla (Feb 2, 2009)

By the way, the fan is a 4" model, not a 6" model.


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## Dj823cichild (Mar 30, 2009)

Thanks for the update! :thumb:


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## ben1988 (May 2, 2009)

I have an ac unit running in the room adjacent to the room with the 150 and the 29 is in the same room. room is at 75 but the tanks are running HOT. the heater is off but my water only cooled down to 80. i dont think the magnum 350's are heating the water that much since i can touch them no problem. no top on the tanks at all as of right now but the 55 that only has drift wood in it is running at 70 just like the room!!!!


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