Water temp remains consistently high

[clone]

hi,

I only recently bought a thermometer and realised that my water consistently remains between 29-30C. I have suspecting that my lights are causing the problem. (A 15W FL and a 11W table lamp on 2 feet tank) But after I switch off the lights for the night, the water temperature still remains at 29C the next morning. In contrast, my pail of water next to the tank remains relatively cooler.

The temperature remains at this level even if the weather turns cool or when it rains. (Even when the ambient temperature is 27-28C). The only way to cool it down is to turn on my air-con but very expensive lah. Does anyone else have the same problem?

I am now thinking of installing 2 cooling fans, but I have another logic question. If the ambient temperature is at 29C, how does blowing 29C air into the water helps to cool down the water?? No doubt evapouration will take some heat away, but do not think it would help much.

Just asking fellow enthusiasts who have installed fans to comment how much does the fans really helps.

Thanks,
clone

[robin]

I have installed one fan and the temp drops to 26-27. When i use 2 it drops to 25-26. I think the issue is not "blowing air into the water" but providing air movement to carry away the heat.

Water is a slow conductor (I am not a scientist correct me if i am wrong). Therefore, any change in temperature takes a long time to reflect in the water. Give it about an hour i think you will see the difference.

Anyway, the fans works for me. and I have 2x30W fl tubes. My tank always runs cooler than the ambience.

Regards
Robin

[clone]

Robin,

Your info will certainly encourage me to get the fans. But my logical brain is still confused, pardon me for asking this stupid question. With the water and air at the same temperature, then there would not be an exchange of hear right?

Also now without any fans, I am losing 10-15% of water due to evaporation. With the fans, this make the tanks lose more water. How often you do need to top up the water?

regards,
clone

[Simon]

cooling comes from evaporation and also improve air circulation between the water surface and your lights. most of us, do use either DC or AC fan to cool our tanks

[bluezing]

hehee....sounds like a science lesson going on.btw...mine is 29 degrees most times also.once...it drops to 28...and my rummynose enjoyed it!their nose turns really red.

[tawauboy]

----------------
Also now without any fans, I am losing 10-15% of water due to evaporation. With the fans, this make the tanks lose more water. How often you do need to top up the water?
----------------

how long does it take to loose 10-15% of water?
with fans, you can expect to top up water everyday or every alternate days. it depends on the number of fans used and angle of fans relative to water surface.
you can expect your tank temperature to drop about 2-3 degrees when you have cooling fans installed.

[clone]

I now lose 10-15% in a week. So every weekend, I just top up the water.

If you change water every day or alt day, dun you have to leave a pail of water for your aquarium every day to age? (for the chlorine to escape)

[bluezing]

and the water bills will be up also.[]

[CT]

I am presently using a AC fan for my 2ft tank and the temp for my tank remained at ard 27 deg. mi only on the fan only when the lightings are on(to save a bit on the electricity bill. haha!) as for the evaporation mi only top up the tank around once every 2-3days.

[robin]

I lose about 10 - 15 litres every 3 days due to the DC fans.
One solution i using to save water bill is this
I buy the square head tap key and get water from outside my house near the garbage chute ssssshhhhhhh.... don't tell anybody later government catch me.

Cheers

[bluezing]

whahaha...u jialat liao...they r coming for u!

[loupgarou]

Evaporation is very difficult to estimate, and depends on the surface area for evaporation and the relative humidity of the air. Each kilogram of evaporated water removes 2258 kJ from the water, which is a significant heat loss, and this can be converted to watts noting that 1 watt = 1 joule/sec. While it is difficult to predict the rate of evaporation, if we know the mass of the evaporated water and the time it took to evaporate the water, it is possible to estimate the heat transfer.

Empirically, evaporation loss can be estimated from the humidity ratio increase and is approximately 0.18% per degree C decrease in water temperature. (Lindeburg, 199

--------------
basically, the more water you evaporate.the faster the tank will cool.

if you can evaporate eg: 50% of a two feet tank in 1 second. I guarantee the rest of the water will become ice.

-
you can see the phenomenon: eg: release lots of gas from your co2 tank, your co2 tank will cool and even form ice. reason: evaporating the liquid co2 removes kinetic energy (heat) from the rest of the liquid.

[subxero]

----------------
On 7/20/2003 1:46:24 PM

hehee....sounds like a science lesson going on.btw...mine is 29 degrees most times also.once...it drops to 28...and my rummynose enjoyed it!their nose turns really red.
----------------

Bluezing.. your rummynose got runny nose on warm weather?
[:0]

[vinz]

Have you guys ever checked how much you're paying for water?

For my 6 ft tank, I loose about 10 litres of water to evaporation every day. That's 300 litres a month.

At the maximum rate, before taxes, PUB charges $1.40 per cubic meters of water.

300 litres is 0.3 m³, which works out to $0.42 a month.

Do you really need to steal water?

[magic1980]

yo clone, i got the same problem as u.
always 29- 30
then i install a AC fan.
not can get 27....

i think its a must.
cos if i am not wrong, at 29, ur shrimp will die very very fast.

[eric_kclee]

Hi Clone,

It may sounds ridicules!
My friend actually had this experience.
Cool day warm day always read 29deg....
Then he took out the thermometer and measure the ambient...also read 29deg....get it?

He threw the junk thermometer and buy another one.

[vinz]

A bit off-topic... I've had yamatos living in 30 to 32 celcius water. However, from an old discussion in AQ, shrimp in larger tanks (3ft or bigger) tolerate warm water much better then smaller tanks. My personal suspicion is that bigger, deeper tanks are slightly cooler in shaded and deeper parts of the tank.

One thing is for sure, at higher temps the fishand shrimps were more susceptible to diseases, etc.

[clone]

Seems like I am going either to buy or make one cooling fan very soon. Although my temperature is always between 29-30, my shrimps are doing very well in my 2ft tank, but I am not know what type of shrimps are they. The whole transparent type, the LFS gave them to me free. []

eric,
I do not think the thermometer is faulty coz when i turn my air-con full blast, it shows 24. Also using my hands, I could feel that my pail of water next to the tank is significantly cooler. Any difference after your friend bought a new thermometer?

Thanks for all the info so far

[sherchoo]

I have to stress Vinz's point on the effects of temp on shrimp. 29~30 deg will not kill your shrimps, most of the time it's the temp swing that kills the shrimp. Most lfs displays the shrimps in tanks without cooling. That's why whenever we place the newly purchased livestock, it's important to float the bag for awhile to allow them adjust to their new home. I've myself kept Yamatos in temp up to 34 deg water... no "boiled" shrimps then. So please don't be misled that shrimps will die at high temp.

Another point is, that 29~30 deg is not considered 'high' temp. Most plants and fishes/shrimps should do well in that temp.

Sorry, but a bit off topic.

Clone,
If there's nothing wrong with your tank, why do you need to cool your tank. For me, I cool my tank as plants like Hottonia, Moss and Tonina prefer cooler temperatures. My fish never had problems with your so called 'high temp'. Do let me know.

[bttay]

I have the same situation too: water temperature remains at around 29 and 30 degree.

Cooling fan will cause the water to evaporate faster. But won't it make the water more concentrated and thus change the hardness and pH?