What temperature is your heater set on?

I don't think so hey...the heater comes on not that much...been watching it carefully during the day the red "on" light hardly comes on...afternoon & early morning it comes on for few seconds & goes off then

 

Referring to the fact that you've set it to 28 yet your water temp is only at 25-ish. I also use via aqua heaters on my other tanks, set to 24 and I get a 24 reading. From what I've read, and I may be wrong here, is that you need 1watt per litre. For instance, by 90l has a 100w heater... same as my 80l. My 40l has a 50w heater and my 180l has a 200w heater.

 

Yes I agree...taking in consideration that my tank volume is 340L...measuring true water displacement volume is @ 303L...so ya , 1w per L is spot on...currently the temp is at 27 now as we speak...maybe the stick on thermometer is not 100% accurate...I have set back the adjustment knob to between 28 & 26 giving me 27degreesC...also it is quite hot today , and heater has not come on yet

 

100% it could definitely be the thermometer as well

 

Thermometers I guess never is 100% accurate

 

Yeah I think the better quality ones are more accurate. I might have been lucky with mine, no issues yet... touch wood.
I have a digital thermometer meant for personal use... actually want to give it a test on the tanks and see how accurate it is.

 

I had a Boyu digital one...but I don't think it was on , could never get themp up above 24 in the tank even with heater set to 28...I like the stick on Boyu , it's a brand name at least

 

The digital one I have is for taking human temperatures hehehe just curious to see if it would work for a tank. Would be good for comparing with the glass ones I currently have to see when they need replacing.
Do you have the stick on strip? I don't know how accurate those are, so that might be the reason for the readings you're getting.

 

Hi...I just our baby's digital meter hahaha , it doesn't register temps below human temperature(36-39) yes I have a Boyu stick on strip

 

hahaha nice one, ok good to know... won't waste my time
Are you able to get yourself a glass one (even one to borrow), just to compare temps?

 

No not yet...gonna look for one tomorrow...any suggestions to name brands? Would u say glass is better than the stick on?

 

Some interesting reading Digital or Glass thermometers?

 

thermometres

 

My take on thermometers:
Go to your Lfs take a bunch of the identical glass thermometers, I'll guarantee there'll be at least a 2 degree discrepancy between low and high, add all the different makes available and you'll be up to 5 degrees, perhaps even more. The median temp is probably correct, that's the one you buy, same applies to the submersible digital jobs, and they all fail within a month. The stick on ones are notoriously inaccurate.
I have two glass thermometers in each tank and hope I'm in the ballpark..,,

 

This is exactly what I was going to do...

 

I use a 2 off 500watt heaters. No idea witch brand. I only use one heater of the 2 for my tank. Winter times I set it about 34deg, estimate water temperature between 24 and 26 deg. I use a stick on thermometer but they are so useless. From end September I switch off all the heaters till about April. The oscars normally show quickly if your tank is to hot or to cold

 

I'd go with this... the glass ones are extremely cheap. I bought no name brand ones.

 

The glass thermometers is nice and cheap and normally works well. The problem I've got is my fish vandalize anything I put in the tank or try to eat it.

 

I have two Via Aqua heaters set to different readings, one is 28 and the other is like 30! But my actual water temp is 26-27. This is the exact reason why i want to buy a new heater or two. Im looking for accuracy, and Im leaning toward Eheim Jager. Are these heaters accurate? Does the reading correspond on thermometer to the heater settings? Anyone know?

 

I have my heaters set at 28 and my thermometers read 28

I use the cheap heaters, cant think of the name now.
I have found that the most accurate thermometers are the glass ones but you get 2 different glass ones.
The ones that have mercury at the bottom which have been around for years and the ones which have a red liquid which I am not sure what it is.
The ones with the red liquid are very, very accurate. The only problem is they are made of thinnish glass and break easily so with oscars it is a bit of a problem so I have one of the old ones in just for monitoring but if I want to double check I use the one mentioned above.