# temperature issues



## BrianD_IL (Sep 27, 2013)

I am cycling a new tank (125gal) and i am running into temp issues. I am using 2 300w marineland heaters, they are set to 78, on the heater themselves it reads temp at 78 also. BUT both my digital thermo and little cheapie thermo are reading 83. I use same brand heater (200w) in my 55 gallon and have no issues, it stays right at 78. I dont have my lighting on which are the single bright leds so that cant cause anything. I am using the glass top on it, and have managed to perfectly cut out the back plastic piece around every so its pretty air tight. Could this be holding in extra heat causing the higher than set temp?


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## Iggy Newcastle (May 15, 2012)

I use a single 300 watt heater in my 180 gallon. I used a single 250 watt in my 125 gallon.

It depends on where you're getting your temp reading and your brand of heaters, but I would shut one down and see how things settle out after a day. One 300 watt keeps my tank at a cozy 78-79...

Stupid question... is it a type of heater that requires user calibration?


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## ozman (Sep 7, 2012)

yeah i was thinking like iggy re : does it require calibration.


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## BrianD_IL (Sep 27, 2013)

no, read thru the little pamphlet that came with the heaters. Just says to plug in an let sit for awhile as to not damage it when you turn it on. The water is noticeably warmer than the 55 upstairs, and my glass top has all kinds of condensation on the bottom side. Turned one off, and one down to 75 since Iggy's post and it has maintained at 81 all night and into this morning. Gonna leave for a few hours and when i do, going to open one of the lids just to see if its trapping enough heat to cause this


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## Schticky Schnauzer (Aug 2, 2013)

Are your lights creating heat? I recently bought a 135 with 4- 3 foot lights on it, and a 250 watt aqueon heater. The temps with it wouldnt drop below 81 with all 4 lights on. I turned 2 of them off, and the temp would normalize with the setting on the heater. Thusly...I am building a hood with led lighting.


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## BrianD_IL (Sep 27, 2013)

i did notice one of the new heaters was on even though the tank temp was much higher than the setting. Unplugged that one and set the temp on dial to 78 on the remaining heater. Temp is very slowly dropping now, first time its been under 81. So thinking I had a defective heater.


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## BrianD_IL (Sep 27, 2013)

i apparently got 2 defective 300w heaters from marineland. One just flat out heats, which i guess i can use to heat the new water going into the tank, and the 2nd heater, is currently set at 75, and keeping the tank between 77.9 and 78.1 for the past few days. So that one is 3 degrees off.


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## Iggy Newcastle (May 15, 2012)

That sucks. I heard they have good customer service...


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## BillD (May 17, 2005)

Bad calibration doesn't make a heater defective. If it holds a temp that is different than the dial, the calibration is off. Set it so the temp is what you want and ignore the scale on the heater. I have several like that. Some can be recalibrated others can't. Old style HOB heaters didn't have a temp dial. You adjusted until the temp on the thermometer was what you wanted, and it would then hold it.


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## gverde (Mar 3, 2010)

I wouldn't use the heaters temperature scale as an accurate representation of the actual temp in your tank. I've had heaters that even by calibrating it that it was still off a few degrees. As long as the heater can hold a steady temperature after a day or so it should be fine.


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## BrianD_IL (Sep 27, 2013)

well i bought another heater, different brand, different wattage, and in the end the same issue. Now mind you, the lights arent on, so there is no additional heat coming from anywhere, and its in the basement of a bi-level house where the air temp is always on the cooler side. BUT with new heater, have it set at 78..tank was at 77.9. Put it in, waited an hour before plugging it in, and it kicks on, temp goes to 78.1 in tank and it shuts off. Sounds great right, last night i checked it, it was 78.4, this morning at 78.8 at the crack of dawn, then just a bit ago, checked it again, 79.6....What the bloody heck??/

So i got pissed, put the 2nd heater back in that kept it at 78.1 even though the dial on the heater has it set at 75. Guess I am gonna go with that for now, not sure what else to do? I moved the heater by one of the inlets for the XP-L, moved it to where i could direct the outlet to more or less get some water movement past it and still the same. tank temp reads the same on either end of the 125...it holds steady for a bit, then starts the slow march up to or past 80 no matter what.


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## Schticky Schnauzer (Aug 2, 2013)

another thought to consider...is the thermometer. mine gets crazy when the batteries get low.


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## ozman (Sep 7, 2012)

Schticky Schnauzer said:


> another thought to consider...is the thermometer. mine gets crazy when the batteries get low.


perhaps have the old glass tube type as a back-up to your battery operated thermometer, or two of them that has the battery replaced at totally different intervals.


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## brinkles (Jan 30, 2011)

I think you're asking a bit too much of $30 heaters! Anywhere within a few degrees of 80 will be just fine for your fish, and any heater which can hold in that range is a winner. I don't have any that hold a temp that matches the dial.

If your heater fails "off" (they never do) and the tank falls under 70 for an extended period, you may have to deal with some stress related illness. You'll catch this before it happens though. If it fails "on" (this happens to everyone, eventually) everything in your tank will die when the temp gets somewhere above 90, and it happens fast enough you'll be lucky to catch it.


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