I'm wondering if my sump pump motor could be heating up my water causing me to have problems with high temps? The water in FL does come out of the tap at 84 degrees but the temp in the house is around 75/76 with the A/C. I can not get my tank to go below 83 without adding frozen 2 liter bottles to the sump tank.

I just set up a 2nd 29 gallon tank filled 1/2 with water from my existing tank and 1/2 from the tap. The temp in there is 73. It is in the same room as the other tank. The 120 gal tank is at 83. No heaters currently running in either tank.

Why the temp difference??

P.S. Yep, I'm starting a 2nd tank and will be breading either Guppies or Mollies... can I do both in the same tank???

It could be something heating the big tank. However remember that a small tank will equalise with the room temperature quicker than a big tank, when the temperature goes up a lot my goldie tank temperature goes up quicker than my 180g. Does your air con keep the room temperature the same 24hrs, if it does then it sounds like something heating the tank

I would of thought that a pump shouldnt heat a tank though unless it is faulty

I doubt very much whether the pump is heating the water. Have you tried another thermometer to see if it shows the same reading?

Yep... I have a digital, mercury and one of those stip thermomters.

yes, electric motor that runs the pump releases heat and increases water temp in the
tank. during hot weather, an air bubblers helps to lower the temp and at the same
time, increases the oxygen dissolve in the tank.........

This may be a stupid question but have you actually put your hands on the pump to see how hot it is? I use an Eheim pump and that doesn't appear to have any affect on the water temperature, but then again you are talking top-quality.

here is one thing i suggest to those who have an FX5...... during cold weather,
try to touch the lower portion of the canister where the motor is located..
you will definitely will feel the area to be warm... not realy hot because
there would be heat transfer between the motor and the passing water....
any cutting of magnetic flux that make the motor runs (winding and armature) will
produce heat....

OFL wrote:


Not a stupid question... it is hot to the touch. Always has been. This is what it looks like. I don't remember the specifics but I know you and I talked about it before when I got the tank.

if it stays a trouble, maybe getting one of these babys might be an idea.



IMO any pump will give off heat to your water, that's why i got this pump for circulating the water in a central heating system on my tank.
It was chosen for it will eliminate any heat from the pump going into the water.
I just don't know if you can get these kinds of pumps at your country.
And they may cost some bucks but will have 10 bar of pressure at max and could pump the water up 3 stories high!
lol, i never dare to put the control lever on 3...
Maybe worth looking into,B.
I suspect your pump to be the source of the heat.

If the pump is hot to the touch it sounds to me like it may be heating the water passing through. I would get in touch with the manufacturer and see what they say!!!

My sump use's a big submersible pump in the final chamber and has caused me no grief
IMO an external pump would have to be dam hot to generate enough heat to warm up the water in the actual pump / impeller chamber depending on the rate the pump pushes the water through gal /lt's per hour if the motor driving the pump is that hot it would die within a day or 2 :angry:

I doubt very much it's the pump it would have died due to crook bearings etc

I work with various pumps being a fitter but hey I could be wrong

Unless the pump is in a cabinet under the tank the residual heat from the motor could create a thermal under blanket so to speak

cheers Gazza

I hate to say it but I think the pump might be my problem. If you guys only knew what it took to get this sump system up and running! Those of you who have followed me through my 900+ posts know what I went through to quite the thing, stop leaks and install a shut off valve. The thought of trying to replace this pump makes me cry! DAMN... no crying smiley !!! How about it makes me want to !!

Noddy... come do this for me please !

Brooksie