Serious problem

[Diesel3443]

FWIW, both my tanks (60cube and 14g aquapod) temperatures only fluctuate 78-80 (House is a constant 75-76) with no heater at all except for the 4 cold days we get a year

 

[Dashylock]

There is no reason for a heater in FL at this time. Remove

There is no reason for a heater in FL EVER! Even when it dropped down to the 40's a few months back my tank never dropped below 72F

 

[Rogger Castells]

Guys, with regards of the heater, it's true that in most cases there is no need for a heater, specially if you have a large tank which temperature fluctuates very little, however, it could absolutely be needed in a small tank, even in south florida, specially if the tank is kept in an office or a house that keeps the temperature very low, these small tanks can bring the temperature low enough to wipe out all the fish.
Now, from what I can tell, it could have been several things or combination of things, Jay could you expand on what was tested, when and who tested the water? also, were the fish floating or laying on the bottom, I am guessing that a hermit crab died and the ammonia spike produced a chain reaction that in a few hours could have wiped out everything.

 

[subbyjay]

Rogger i went to beverlys pet center and allpets to test the water just to see if there would be any differnce in the reading but both were the same. They did their regular water testing with the test kits. They tested for everything that could be tested with what they had, an everything was laying at the bottom there wasnt any dead fish floating

 

[AquamanE]

There is no reason for a heater in FL EVER! Even when it dropped down to the 40's a few months back my tank never dropped below 72F

I would normally agree with Dashy and others that heaters are not necessary in FL. However thisis a 5 gallon tank. Temperature swings are difficult to control in such small tanks like Rogger said.

I do agree with others thought that temp nor voltage should be looked at first. More like foreign substance and or viral/bacterial introduction.

 

[Rogger Castells]

Well, it sounds like the dead hermit crab or a spike in temperature high or low could have caused your mass death, with out knowing exactly what these places checked for it is hard to determined for sure.
check you heater to make sure it is working properly, set it to the temperature you want, place in a small container filled with water add ice to see if it turns on, add hot water to see if it shuts off, make sure there are no cracks on the glass before you test.

 

[subbyjay]

I have one of those mini sub heaters without a dial, its programmed for up to 5 gallons but i had an extra one thats new so i swapped them out to be on the safe side.