Canister Filter Heating water to 80° F

Utar

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For my 55 gallon aquarium I have these two canister filters hooked up, small pre canister filter and large canister filter. I don't have a heater in the tank nor is there one built into the canister filter. But yet I during a water change I can get the water temperature down to 78° F or a little less. The water always heats back up to around 80° F. I keep room temp at around 75.

As anyone every experienced this before related to your canister filter heating up the water?
 

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Is it the filter or the lights heating the water?
Lights will warm the water up. If the filter is actually warming the water, then it is faulty and has over heating problems and should be replaced.
 

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For my 55 gallon aquarium I have these two canister filters hooked up, small pre canister filter and large canister filter. I don't have a heater in the tank nor is there one built into the canister filter. But yet I during a water change I can get the water temperature down to 78° F or a little less. The water always heats back up to around 80° F. I keep room temp at around 75.

As anyone every experienced this before related to your canister filter heating up the water?
I had the complete opposite happen lol I upgraded my canister filter and seemed to cool my tank I put it down to the filter was pumping my tank volume too fast for it to heat up
 
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Utar

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Is it the filter or the lights heating the water?
Lights will warm the water up. If the filter is actually warming the water, then it is faulty and has over heating problems and should be replaced.
You could be right about the lights so what I will do is leave them off to see if the temp in the tank cools down. I have two light strips that are setting directly on the top covers which are not glass but cut from a sheet of green house roof panel. I have two NICREW ClassicLED Gen 2 Aquarium Lights, one 48" and the other 24". I will come back an update what I find out if it is the lights or the canister filter.
 
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Utar

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I left the lights off long enough to get an idea of it is the lights heating the water. Yes and no, the lights contribute to around 1° of heat. Right now we are experiencing cooler weather in the 50° F range. So last night when I went to bed the water temp was 80°F. The heat for the house was turned down to 70° for the night. When I got up this morning the water temp in my 55g was 78.3. Over the eight or so hours that I slept I feel the water temp should have been lower then 78.3. So I still believe the canister filter is heating the water.
 

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hmm, did you actually do the math on heat transfer? 55g of water can retain heat for pretty long, and the temperature differential from 80 to 70 is not that much. additionally, glass is an insulator, so over 8 hours, I would not be surprised if it only fell 2 degrees. https://www.engineeringtoolbox.com/overall-heat-transfer-coefficients-d_284.html

I have zero actual intuition on these numbers, but it seems plausible to me that it could still be the lights and you are just not seeing a very large difference due to the relatively short amount of time and the small temperature difference.

I could also be completely off base too, but just wanted to say that I would not yet discount the lights as the main source.
 
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Utar

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hmm, did you actually do the math on heat transfer? 55g of water can retain heat for pretty long, and the temperature differential from 80 to 70 is not that much. additionally, glass is an insulator, so over 8 hours, I would not be surprised if it only fell 2 degrees. https://www.engineeringtoolbox.com/overall-heat-transfer-coefficients-d_284.html

I have zero actual intuition on these numbers, but it seems plausible to me that it could still be the lights and you are just not seeing a very large difference due to the relatively short amount of time and the small temperature difference.

I could also be completely off base too, but just wanted to say that I would not yet discount the lights as the main source.
I guess the only way to really tell if it is the lights is to leave them off for a couple of days, but these are the second brand and type of lights that I have used. The first where no where near as bright, hence the reason I changed them. Still the temp was up in the high 70's to 80.

When I first got up this morning as stated above,the temp was 78.3 a waited a couple of more hours before turning the lights back on and the temp had not changed. Now that it has been a few more hours since I turned the lights on the temp as risen to 79.8. But 78.3 without the lights is still a bet high in my opinion.

I feel the canister filter is heating up the water then the lights are also heating up the water which always stops heating right at 80.2 and never goes any higher.... kinda weird.
 

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Hmm.. LEDs will add 'some' heat to the water but, they are far cooler than other lighting options. If you rule out the canister (we'll get to that) and still suspect the lights, try some floating plants or you may be able to add more distance between the light and the water (depends on setup).

Since you mostly suspect the canister (have never used a canister personally) you could take it apart for a deep cleaning. If there is gunk or anything blocking the impeller from turning or significantly slowing it down it could cause the motor turning it to overheat from pushing the energy it's suppose to without it exchanging at the rate it's meant to. Your water moving through the canister works to keep the motor cool and would naturally absorb some of this extra heat as it moves through.

Just spitballing really, like I said never had a canister filter but they're still just a small electric motor and impeller so I'm sure they're prone to common issues any motor/impeller might get.

*Edit: in the below article, scroll down to the 'servicing your canister filter' section and it actually mentions this exact thing I was discussing

 
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Utar

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Hmm.. LEDs will add 'some' heat to the water but, they are far cooler than other lighting options. If you rule out the canister (we'll get to that) and still suspect the lights, try some floating plants or you may be able to add more distance between the light and the water (depends on setup).

Since you mostly suspect the canister (have never used a canister personally) you could take it apart for a deep cleaning. If there is gunk or anything blocking the impeller from turning or significantly slowing it down it could cause the motor turning it to overheat from pushing the energy it's suppose to without it exchanging at the rate it's meant to. Your water moving through the canister works to keep the motor cool and would naturally absorb some of this extra heat as it moves through.

Just spitballing really, like I said never had a canister filter but they're still just a small electric motor and impeller so I'm sure they're prone to common issues any motor/impeller might get.

*Edit: in the below article, scroll down to the 'servicing your canister filter' section and it actually mentions this exact thing I was discussing

Just a couple of weeks ago I did take down both canister filters the small one and the large one. Cleaned them both, lubed the impeller but did not help with the temp increase.

I now know it is indeed the canister filter without a doubt. At 7pm last night I did a water change, after adding clean water the temp in the tank was 75.8. I left the lights completely off the top of the tank, and at 10:30pm the water temp read 78.4. Just checked it again at 12:30am and the temp now reads 79.1. The weather here is in the mid 50's and inside house temp is around 72. I also I have two thermometers on my tank and they both agree within a + or - 0.3.
 

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Just a couple of weeks ago I did take down both canister filters the small one and the large one. Cleaned them both, lubed the impeller but did not help with the temp increase.

I now know it is indeed the canister filter without a doubt. At 7pm last night I did a water change, after adding clean water the temp in the tank was 75.8. I left the lights completely off the top of the tank, and at 10:30pm the water temp read 78.4. Just checked it again at 12:30am and the temp now reads 79.1. The weather here is in the mid 50's and inside house temp is around 72. I also I have two thermometers on my tank and they both agree within a + or - 0.3.
Oh jeez, that's crazy.. which canister do you suspect? Maybe it is just one of the motors overheating/malfunctioned..

They've never been ran dry right? You seem like you know your equipment so hate to ask, helps to rule out possible issues with the motors though - as that's the only thing in there that could build heat (I think at least) unless something near the canisters are heating them up externally.

*Edit - just thought of this too: if the filters/motors in them are older, it could just be a motor wearing down and pulling too much energy to keep it's set pace. Seems more unlikely, but not outside the realm of possibility.
 
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Utar

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Oh jeez, that's crazy.. which canister do you suspect? Maybe it is just one of the motors overheating/malfunctioned..

They've never been ran dry right? You seem like you know your equipment so hate to ask, helps to rule out possible issues with the motors though - as that's the only thing in there that could build heat (I think at least) unless something near the canisters are heating them up externally.
The small pre canister filter has no motor, the entire setup is driven only by the motor in the larger canister filter. I have read through a bunch of reviews on amazon about this canister filter and I found only one person saying it increased their tank's water temp. So it could be a colossal stroke of bad luck that I would be one of the only few people that have had this problem using this filter..

One of the things I could try next is removing the small pre filter and see what happens, but I will either have to buy some more hoses or get a connector to put the intake hoses back together where I split it up to install the small canister.
 

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Use your hand to touch the motor on the outside of the filter. If the motor is hot then it's warming the water. If it's not hot, then it isn't.

As mentioned by mcordelia, water holds temperature really well and a large volume of water (55 gallons/ 200 litres) isn't going to change much overnight. Especially if the room temperature is close to the tank temperature.

During the day the house temperature will go up by itself because the air temperature warms up during the day, and this will contribute to the water temperature rising.

The only way to tell if the filter is warming up the water, is to set up a second tank right next to the one in question. Have exactly the same water volume, gravel, filters, pumps, etc, and leave them to run for 24-48 hours. See if there's a difference in the temperatures after that. If one tank is warmer, then the filter might be contributing to it. But my guess is there is nothing to worry about unless the outside of the filter's motor is hot.
 
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Utar

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@Colin_T thanks for the reply. Yes when I touch the top of the canister the motor is warm. Like I said earlier I now know it is the canister because I left the light completely off the top of the aquarium and this morning the temp was 79.7 which was 75.8 after the water change last night at 7pm. So that is a 3.9° increase just with the canister filter running and no lights. Looks like I am one of the unlucky few that this has happened too. I am going to start looking into another canister filter. I don't have a lot of money to spend on an expensive one like the fluval fx4. I would like to stay with a four stage filter if I can, because I have two trays filled with bio-media ultimate and need the first two for filter pads etc.
 

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@Colin_T thanks for the reply. Yes when I touch the top of the canister the motor is warm. Like I said earlier I now know it is the canister because I left the light completely off the top of the aquarium and this morning the temp was 79.7 which was 75.8 after the water change last night at 7pm. So that is a 3.9° increase just with the canister filter running and no lights. Looks like I am one of the unlucky few that this has happened too. I am going to start looking into another canister filter. I don't have a lot of money to spend on an expensive one like the fluval fx4. I would like to stay with a four stage filter if I can, because I have two trays filled with bio-media ultimate and need the first two for filter pads etc.
You can likely contact the MFR and inquire about purchasing (or where you could purchase) a replacement motor. One of the bigger LFS' in my area has a big rubbermaid bin of spare filter pieces you can dig through, usually has motors in it. Could try calling around lfs' near you to see if they have something similar.

Should save ya some money.

Some of the thrift stores in my area sell crazy aquarium equipment for cheap too, because they don't know what they have (I mean like $300+ setups when they were new, selling for like $30-$50). If you do decide to get a replacement canister, could try looking around places like that, or even pawn shops (maybe) if you have the time. Might find a gem.
 

mcordelia

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another idea if you still have proof of purchase (for example your amazon confirmation email) you could see if the manufacturer would honor some kind of warranty / lemon concept and send you replacement parts for free, if they stand behind their product at all. That's assuming you haven't been running this filter for the past 10 years, in which case it may just be reaching the end of its lifecycle.
 
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