Pump elevating tank temp

[Orthopod]

My large ray tank has gradually been increasing in temperature because of the pumps.

I run a jebao dct 15000 and th older model dcp - 20000.

Does this mean the pumps or one of the pumps is failing? And if not, any suggestion on dropping the temp 2.5 degrees to compensate?

Thanks for the advice.

 

[skjl47]

Hello; Curious as to how you have determined the pumps are the cause of a temp increase.

 

[Orthopod]

Heaters are turned off and never seen a thermogenic Stingray, lol.

In all seriousness, I’ve also noticed that the efficiency of the pump has decreased as my ultima 2000 has a pressure gauge that appears to be decreasing which has also clues me in.

 

[skjl47]

Hello; I guess I am curious about your opinion as to how a pump can add temp to a tank. From my physics studies many decades ago there was a demonstration showing a mechanical way that moving blades in a tub of water would cause a slight increase in water temp due to mechanical action (friction I think). But that would have (should have been maybe) been a constant from the first use of such pumps when new.

Are the pumps enclosed in a cabinet under the tank perhaps? I can see transfer of heat that way.

Back to the mechanical action of an impeller causing a temp increase. I would look for restrictions in the tubing. Especially in the intake side feeding the pumps since the pressure is lower.

I suppose if the impellers and shaft are metal then the aged electric motors might be running warmer and some extra heat is being transferred thru the impeller shaft. Maybe friction in the shaft bearings.

My initial thought was the season. It is August and my tanks are at high temps with all heaters unplugged.

 

[Drstrangelove]

My large ray tank has gradually been increasing in temperature because of the pumps.

I run a jebao dct 15000 and th older model dcp - 20000.

Does this mean the pumps or one of the pumps is failing? And if not, any suggestion on dropping the temp 2.5 degrees to compensate?

Thanks for the advice.

In most circumstances, whenever you have objects in the water (fish, pumps, heaters, etc.) that have temperatures that are higher than the surrounding water, then heat transfer will occur. However, deducing that a rise in water temperature is only caused by something inside the water would only be possible if one has maintained ambient temperature at a constant level, kept water volume and turbulence volume, kept evaporation constant, and also eliminated any external source of energy (e.g., sunlight.) As S skjl47 has said, summer seasons would naturally create higher ambient and greater amount of external energy sources.

Assuming you have kept room temperature constant, blocked off higher external energy sources and added nothing else to the water, it's reasonable to think the pumps are the cause. This doesn't however mean the pumps are defective even if they are producing more heat. The pumps could for example be working harder (thus producing more heat) due to filters being more restrictive (e.g., smaller micron filters or dirtier), being put on higher settings, or having been moved to locations where the pump would work harder.

You could also have less water in the tank now, or have less evaporation, which could also lead to a rise in temperature. Simply reducing the water volume would naturally cause the pumps to cause more heat, while covering areas where there had been evaporation would make the heat rise since the tank would now be more thermodynamically efficient.

The temperature in some of those circumstance might be reduced by:

1) reducing ambient temps (e.g., air conditioning)
2) blocking external energy sources (close the blinds/drapes)
3) cleaning the filters
4) removing other heat sources recently added (e.g., UV filter, wavemaker)
5) raising tank volumes to the prior level
6) increasing evaporation (place a fan blowing across the water surface, or even the side of the tank)

Of course, getting a new pump of the same design might solve the problem, but in many of the circumstances above, it would have no effect at all.

 

[Fish Tank Travis]

Just to be sure, have you checked that the thermometer is accurate? If it’s digital, then it could be failing.

Can you please provide more info on the setup? Tank size, sump size, heaters, heater controller, etc.

 

[Orthopod]

I apologize for the earlier joke but another piece of info, I have 3 other tanks in the room that haven’t changed temp.

 

[nzafi]

Yes it’s possible. On my 530g I’m running a gold snapper/dart for my ultima and two eheims inside the tank. The combination heats my water to 80-81 degrees. I’m also runnng a cold water drip which in winter time will hopefully bring the temperature down a bit.

It is know that pumps add heat to the water depending on brand. Saltwater guys are much more sensitive this though than us freshwater guys.

 

[duanes]

I've had Mag Drive submersible pumps raise temps when running well, enough to not need to use heaters in my tanks in winter in Wisconsin.
When the pumps start to fail, or the volute gets plugged they often get very hot.
I would do maintenance and check them out.
With the Mags, they usually started burning out after 12 to 15 years, and the water temp elevating was my first clue they were failing.

 

[Orthopod]

As per request above, here’s my setup info. Tank is a 450 glass with 150 of sump with ultima 2000 running and Jabao 20000 to ultima out of sump and jabao 15000 running as alternate bypassing ultima.

I live in the Seattle area so I don’t have as huge summer to winter swings as many places. I use 2 digital thermometers on the tank and they are accurate. I also have checked them with my temperature gun I use for water changes.