Tank temperature plummeting

[Falconwithaboxon]

So I've been keeping fish for quite a few years now and this is an issue I've never seen. When I woke up this morning, My fish tank was around 78f and now, only about 4 hours later, it is cold enough the thermometer is not picking up a reading. The thermometer has very limited range, 50f-100f. It is cold to the touch, as if I just put my hand in an ice bath. The fish are most likely goners, but what could this possibly be caused by? No water has been added to the tank today, could my cats have messed with my heater and turned it down low? Is that even an option to make the water that cold on heaters? All my water parameters are correct and have been stable for a long time now. I am entirely stumped and extremely disappointed. I guess a bright side is I get to restart my tank which is fun.

 

[BigBurgassio]

Have you tested the power supply to the heater, checked fuse etc ? Or maybe the heater element has failed.

 

[Ram419]

No a heater wouldn't make the water colder. It sounds like the heater stopped working. As far as how cold it got since the heater stopped working, maybe the tank is in the way of an air conditioner output vent?

 

[Byron]

Missed the above post, I said much the same, so agree with Ram419.

 

[Falconwithaboxon]

I assume it is not the heater I was just wondering if some heaters had a cold water setting, figured they don't but worth asking. There is no AC vent since my bedroom is in the attic and there is no AC up there. It's plummeted way too fast for it just to be the air but there's nothing else it can really be I guess. I have had tanks in that same room that I have ran without a heater and they stabilize to around 60.

If the worst case happens and they do die, is 30 gallons big enough for two goldfish?

 

[TwoTankAmin]

There is almost no way for the water in a tank to bre greatly different from the ambient temperature unless aomethen mechanical is involved, a heater, a chiller etc. Now it may take some time for a tank to equalize with the ambient temp, but eventually is has to with out internal to the tank interference.

What sort of thermometer are you using? Did you feel the water with your hand?

 

[Ram419]

I would suggest getting something like an infrared thermometer to spot check temps. I've found it invaluable.

 

[Falconwithaboxon]

I don't know the brand it's just some cheap thermometer that's always sitting in my tank.
I felt the water of my hand and it feels like an ice bath.
The heater doesn't have any refrigerant so it can't possibly be that. No air vent since I have no AC in that room.
The temperature is slowly rising but I cannot figure out why it plummeted to begin with. I've checked for a heater issue, for an air vent, ask my wife if she put water in the tank can somehow that did it. Any issue that's been mentioned or that I can think of I have checked. I am completely and entirely stumped.

 

[Falconwithaboxon]

I would suggest getting something like an infrared thermometer to spot check temps. I've found it invaluable.

I will look into that. Maybe not the best option but I used a meat thermometer that reads the air as 80°, accurate, and the tank down at 55°

 

[powerdyne6]

Virtually impossible for the water to drop below the air temp unless like what was said above.

I would say your thermometer is broken

 

[Colin_T]

maybe the aliens abducted the fish tank and chilled the room to hide the heat signature of their ship from the US government

 

[Falconwithaboxon]

Temperature has gone up but it still low, 72f not positive what caused it except likely a broken heater

 

[Naughts]

It's advisable to have a spare heater and thermometer.

maybe the aliens abducted the fish tank and chilled the room to hide the heat signature of their ship from the US government

Or fish ghosts?

 

[sharkweek178]

I would suggest getting something like an infrared thermometer to spot check temps. I've found it invaluable.

Those are also handy during water changes. I also use mine when preparing water to hatch baby brine shrimp.

 

[sharkweek178]

So I've been keeping fish for quite a few years now and this is an issue I've never seen. When I woke up this morning, My fish tank was around 78f and now, only about 4 hours later, it is cold enough the thermometer is not picking up a reading. The thermometer has very limited range, 50f-100f. It is cold to the touch, as if I just put my hand in an ice bath. The fish are most likely goners, but what could this possibly be caused by? No water has been added to the tank today, could my cats have messed with my heater and turned it down low? Is that even an option to make the water that cold on heaters? All my water parameters are correct and have been stable for a long time now. I am entirely stumped and extremely disappointed. I guess a bright side is I get to restart my tank which is fun.

What kind of thermometer is this? If it's digital, those can often malfunction.