Water temperature

[maltese falcon]

I have 20g tank with live plants and tetra cardinals.

Though my automatic heater is on the mark of 80F, the temperature of water is keeping on 88F.
I placed termometer on the other side of aquarium, I got the same temperature. I bought a new termometer (I have chosen one wich had the same temperature as the majority of other termometers), I got the same temperature.

What could be the problem?
How long my fishes and plants can stand that temperature?

 

[maltese falcon]

 

[Blucat]

what is your tank made of glass or acrylic? What is your room tempereature. What is your heater wattage. I had a similar problem and it turns out my thermostat on my heater is wrong.

 

[mattrox]

Just turn your heater down a bit. The thermastat may not be accuratley calibrated.

 

[maltese falcon]

my tank made of glass.
my room tempereature ranges from 73F to 95F.
my heater has 100W.
do I have to buy a new heater? (I have in mind to do it today)

 

[mattrox]

If your room temp is 88F then your tank will heat up from 80 to 88. If it is 95 it will heat up to 95.
Don't buy a new heater. just make sure the tank doen't heat. Keep the room temp cooler if you can.

 

[maltese falcon]

If your room temp is 88F then your tank will heat up from 80 to 88. If it is 95 it will heat up to 95.
Don't buy a new heater. just make sure the tank doen't heat. Keep the room temp cooler if you can.

this night I didn't close the window to be sure that room temperature won't rise, so, temperature of the room wasn't higher then 73F, I believe it even dropped down, but water temp was 88F.

is it very dangerous for fishes? will my plants die?

 

[ace1uno_00]

Try to turn down the heater all they way down. let the temp in the tank drop then adjust it up as needed.

 

[maltese falcon]

Try to turn down the heater all they way down. let the temp in the tank drop then adjust it up as needed.

sounds very reasonable. thanks

 

[maltese falcon]

my heater is here, 100W

 

[TankGirl]

Often a sign that a heater is going bad is for it to stay on and lose its thermostatic control, so if it is not shutting off automatically then it is time for a new heater.

 

[maltese falcon]

no, the most of the time heater is off, turning on sometimes for a not very long time.
I did try to set a little lower temperature, but it didn't help.

as mattrox noticed, the thermostat may not be accuratley calibrated
so, I'll follow ace1uno_00 advice: turn down the heater, wait until water temperature drops and try to make temperature adjustment

 

[tetrin]

try to do any temperature changes slowly...about 1-2deg per hour...
otherwise you'll stress out the fishies...

 

[maltese falcon]

I have 84F today and I decided I'll leave that temperature until the end of day. My fishes seems to be well, plants as well... Heater is on the 77F
I still doubt (I don't know why!) that my termometer shows the correct temp!

 

[spongebob69]

I'd be more inclined to believe ur thermometer is accurate and the heater is not. My heater shows a temp setting of about 74 but my digital thermometer shows the temp to actually be about 78.

What brand of heaters have accurate thermostats anyway?

I need a new one for my 90 gallon and am thinking of either getting the Hydor ETH inline one or maybe a WOn Brothers titanium

 

[TankGirl]

Hydors are great, and titanium heaters are also very reliable. I have Ebo-Jagers and Visitherms. A couple of my Ebo's are somewhat long in the tooth now and still going strong, but the company was sold to Eheim so I don't know if these fabulous filter-makers will continue the quality of the heaters. I assume they will.

 

[SteveM]

I still doubt (I don't know why!) that my termometer shows the correct temp!

I'd believe your thermometers, especially if you've used two and they agree with each other.

One of my heaters (Rena Top Light) is set to 70F and is maintaining 79F in its tank. Luckily I found out before I added the fish - first morning I checked the temperature in the tank was 88F. Turned the heater down a little at a time until it got where I wanted it and its been stable since.

 

[pitt420dude]

Can anybody answer Maltese's question about the harmful effects on plants and fish that keeping a temp of 88 degrees will have (other than de-oxygenating the water)? I was wondering myself and am not clear.
Look on the bright side Maltese! At least you dont have to worry about ich!!

 

[TankGirl]

88 is really a bit much for most fish and plants. Plants can handle it and bounce back, but I don't know about the fish. The high temp speeds up metabolism and less oxygen is available, so even for treating ich I don't go above 86. I think discus can handle it a bit better than other fish.

 

[RoK]

If the water's lowest temp only gets to a minimum of 73 F then you don't even need a heater I think. See if you can keep the temp between 75-80 though.