Temperature Controller

[dradttg]

Dear all,

I just DIYed a 6x fan recently and found that it could drop my 2 ft tank's temperature to 25. I am afraid that the water will get too cold and I am running 3x fan now.

Are there any off-the-shelf device that I can use to perform the following:

1) When the temperature in my tank reaches 28 degree, turn on the other 3 fans.

2) When the temperature in my tank reaches 26 degree, turn off the other 3 fans.

Please recommend the brand and tell me where I can get it. Please possible also the price.

Alternative, has anyone come across any DIY articles on how to build such a device.

Thank you.

[lightningstrike]

u should try sim lim tower. ask if the FOX thermostat controller can do......

[Cookiemunster]

Wah bro,

I think you better check with another thermometer cos with the weather these days, achieving 28degrees is fantastic already......and you say 25?????

I wouldn't waste the money as its best to let the temp go as low as possible. And using fans, its not going to be able to go very much more than 2 or 3 degrees below ambient temp.

[dradttg]

Wah bro,

I think you better check with another thermometer cos with the weather these days, achieving 28degrees is fantastic already......and you say 25?????

I wouldn't waste the money as its best to let the temp go as low as possible. And using fans, its not going to be able to go very much more than 2 or 3 degrees below ambient temp.

That was my first reaction too.

I am using a digital thermometer. I used my glass one to check too. Yep 25 degree.

6 Japanese made...more expensive fans.

[ah wa!]

Is your tank placed in an air-conditioned room? When wind from the fans blow at the water surface. Water at the surface absorb the latent heat energy and evaporate causing a cooling effect. Tank temperature will drop to a lower level than the ambient temperature. When the fans continue to blow, forced convection will take place and the surrounding air( higher temp) will transfer some of the heat energy back to the tank water. What I'm trying to say is that an equilibrium state will set in and the temperature will stabilised even if you add more fans.

From the experiments that I've done. A drop of 3-4deg from ambient temperature using fans is about the max(depending on other parameters like ratio of surface area to volume, wave action at the surface etc). I wouldn't waste energy running six fans at the same time. I will shut them down one by one until the point where the temp start increasing then turn on one more fan than at the point.

[ryz]

My tank temp drop to 23 suring midnight with my air con and 2 AC fans on... realised it is too low so I off my fans at night... when I wake the tank temp is around 25.5 - 26...

[FuEl]

Tonight my tank temp is 26.5! Only running on one profantec fan 24/7..

Anyway dradttg...maybe you try running on 3 fans 24 hours? If the average temperature is to your liking then just leave it be? Anyway...won't 6 fans evaporate alot of water?

[ryz]

yea... I run 2 fans evaporation rate like crazy already... and I dun even run them 24/7

[dradttg]

Yep. Water evaporation is almost doubled now. Used to only top up 1.5l once a day when I am using 2 fans.

What I am doing now is split the fans into 2 plugs. 3 fans will be on all the time and the other 3 fans will only go on when my lights are on.

So far my tank has been maintain at 27 - 28 degree.