tank overheating

I have been running a new system for two days now and I am having overheating problems. My thermometers are not calibrated but my cheapie fish tank thermometer read 94F and a meat thermometer of better quality read 92F after I shut the system down and an hour after I added air stones. The system pumps and filters for three 20g tanks that are stacked one above the other on a stand. In addition to the tanks, I have a 20g non-filter sump that has about 15g in it, a sump filter with approx. 5g in it, and an offline wet/dry that typically has less than two gallons. I am pumping with a Little Giant that is rated for 1200gph. At 8ft of head it pumps just over 300 gph which will give me a good turnover rate (less than 10). In practice though, I had to install a bypass to vent extra water back to the main sump. The end result is temperature that slowly creaps up to the death zone. I am actually surprised that I havent had a mass fish kill.

Does anyone have any ideas on how to cool the water other than adding ice all of the time? I did that this morning but 80g of water has a lot of thermal mass and didn't make an appreciable difference.

here are some pics of what I am working with...

The first is the tanks and stand and the second one is my equipment set up (outside).

I made a modification to my system since taking the picture. The bypass pumps back to the black barrel (main sump) because I could not get enough water flow back to the main sump. I also had problems with air churning into the water (causing champagne bubbles) from the pump sucking air. I fixed this problem by extending the return pipes to the bottom of the barrel, cutting the bottom end at an angle, and facing it away from the pump. When I got rid of the champagne bubbles the heat problem started.

plumber892003;476252; said:

I don't see any mention of heaters in your system. What, if any, heaters do you have?

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no heaters, it is all from the pump.

LoTech;476271; said:

edit: you posted more info while I was replying.

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Gotta love it when that happens

I agree with what you have to say about putting the pump inline rather than the sump. The body of it is aluminum and the cord got warm after running it continuously. It is pulling a lot of juice. Unfortunately, the pump is in the bottom of that black barrel and it is not a self priming pump. I was thinking of going through the trouble of sinking a four or six inch pipe to house the pump and then valve it over...I need to give my buddy Rube Goldberg a call (doing simple things in really complex ways) Anyway, I need to replace that pump and I have a Monday deadline. The problem is I won't have the money until two weeks after Monday. My brother just gave me a pump that should do the job until then. It has a plastic housing and shouldn't transfer heat as much. It doesn't flow as much which should be a good thing. It will keep my fish breathing at a good temp.

The bad news is that I have two african cichlids that are not likely to make it to sunrise. One of them is one of my favorite cobalt blues. One of my favorite knives has also partially lost the coloring in its spots. It can't be a good sign.

Mainly I was looking for a way to treat the symptom rather than find a cure. Replacing the pump is the cure, trying to just cool the water wasn't the brightest idea.

Thanks for the input guys,
Ron

meiling;478749; said:

I had the same problem, control the temp of the room the tank is in and put a fan across the top to keep a breeze,that dropped mine enough to be tolerable.

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The good thing is we don't have to use heaters I added air stones, left the lids open and turned the ceiling fan on high. I also opened the ac vent all the way. I got it down to around 86f but I am not sure if that is ok for my knives in the long term.

I was thinking maybe a radiator/heater core and small fan. I also thought of using a small electric cooler that I picked up and turning it into a water cooler. Then I got to thinking...I am putting way too much electricity into the system and then I am going to use more electricity to take the extra back out. In the long run I will be paying for the pump that I really need in wasted electricity.

My brother gave me a pump (very expensive at that) that should have solved the problem. We gave it a test run in my shower and it pumped a good volume at 7 feet of head. The only problem is I have to pump about eleven feet to my top tank. It barely pumps to my second tank Dr. Joe found one at Harbor Freight that looks perfect.