How long should your heater run?

[aquaman67]

I’m using an Inkbird controller and two 100 watt heaters on my 50 gallon softie tank. How long should it take the heaters to heat the water 1° F?

I’ve been keeping my house a little cooler this winter. 66° at night. (Makes for better sleeping)

The Inkbird is set to alarm at 2 hours of continuous heating. The alarm has gone off twice in the last few weeks.

Is running over two hours for 1° too much? Do I need bigger heaters?

 

[Rtaylor]

Why isn’t it just set to alarm at certain temps? Who cares how long the heaters run as long as the temp is in range?

 

[aquaman67]

It’s set for continuous heating in case a heater gets stuck on. It’s also set to a high temp.
Two hours for 1° just seems a long time.

Why isn’t it just set to alarm at certain temps? Who cares how long the heaters run as long as the temp is in range?

 

[I never finish anythi]

If I had a 55g I'd get 300watt heater

 

[Rtaylor]

It’s set for continuous heating in case a heater gets stuck on. It’s also set to a high temp.
Two hours for 1° just seems a long time.

Why not use temp based alarms instead of time based? What type of controller are you using? Inkbird controller will turn off once the temp is over the set point. It can’t get stuck on as the Inkbird kills the power.

 

[Pistondog]

If the heater is on all the time and the temp stable, it might be undersized. But since you mention the cooler ambient, this is the real reason it is on longer.
Why do you care if its on longer? As others have said, no worries until the temp swings too far.

 

[EricR]

Do your heaters have their own thermostats also?
If so, just be sure they're set higher than the InkBird.
If one or both heater is actually turning OFF due to its own thermostat before the InkBird hits its high temp, that wouldn't be ideal, obviously.

For reference, I run 2x 100 watt Eheim glass heaters through InkBird ITC-306A on a 40 gallon tank (so I little smaller).
I also keep my house in the mid-60's at night.
I have my Inkbird continuous run time alarm turned off since I don't really care as long as my tank temperature stays in range, which it does.
Not 100% sure as I don't often watch but don't think mine ever run for 2 hours straight.

 

[Double monti 61]

I use a 100 watt heater in my 15 gallon tank and maintain a temperature between 79.5 degrees to about 80.5 degrees so you might need a heater with a higher wattage?

 

[BeanAnimal]

1 Watt is 3.41 btu/h
50 gallons of water is 420 pounds.

It takes 1 btu to raise 1 pound of water 1 degree F.

Therefore if your tank were fully insulated (no heat loss) it would take 420 btu to raise your tank 1 degree F.

That is ~123 watts for 1 hour.

The aquarium loses heat to the room through conduction, convection, radiation and evaporation.

Your tank loses 8,092 btu for every gallon of water evaporated. It is winter, houses are dry and evaporation increases.

Room temp lower than tank temp - the tank (conduction, convection, radiation) loses heat to the room

How much?

1 - how much water evaporates per day from your system?
2- how many degrees F does you tank drop in 1 hour without heaters.

Lastly - do the heaters really draw 100W or is that just what the label says.

 

[hoffmeyerz]

Definitely keep the time alarm set! I had an instance where our pet rabbit chewed through the temp sensor wire so my apex kept the heater on for like 14hrs straight and heated the tank to 96 degrees. If I had that alarm set I would've caught it.
I would only worry that it may shorten the heaters lifespan. Maybe consider a stronger heater like some others have suggested, I have a 500w on my 75gal, it's usually only on for a few mins at a time.
The time to heat is really dependent on the difference between tank temp and ambient temp, the greater the difference the more heater you need.

 

[vetteguy53081]

I’m using an Inkbird controller and two 100 watt heaters on my 50 gallon softie tank. How long should it take the heaters to heat the water 1° F?

I’ve been keeping my house a little cooler this winter. 66° at night. (Makes for better sleeping)

The Inkbird is set to alarm at 2 hours of continuous heating. The alarm has gone off twice in the last few weeks.

Is running over two hours for 1° too much? Do I need bigger heaters?

It should have or be on a thermostat that regulates when it needs to come on. Two hour and on suggests heaters wattage is Under-sized

 

[workhz]

Animal -I see you fixed gallon to lb. I still think you ought to capitalize the first A in your name

 

[ingchr1]

I run a 125W with a 50W backup on my 40 gallon AIO. The low temperature setting of our house thermostat is set at 64F. I keep the tank at 80.6F. Most of the time the 125W is enough to maintain tank temperature. Last I looked it would run ~20 minutes or so for a 0.3 to 0.4F increase in temperature.

If it's maintaining temperature I wouldn't worry too much how long it's on for.

I'd rather have a just right sized heater than an oversized heater.

 

[BeanAnimal]

Bigger is not better, by any means.

A perfectly sized single heater would run about 80% of the time on the coldest days of the year. It has a bit of headroom for emergency but if stuck on will not rapidly overheat the tank.

Different math and logic can be used when splitting between 2 or more heaters. Beyond the scope of what I am willing to bang out on the iPad.

 

[BeanAnimal]

Animal -I see you fixed gallon to lb. I still think you ought to capitalize the first A in your name

The name came from B E A N A N I M A L
I ironed it onto a shirt for wrestling practice 30 years ago to be funny… letters too close together. Everyone was like “what’s is a bean animal’. I was like… no no Be An Animal. They we’re like “whatever, bean animal’. So i am Bean Animal — but wanted to Be An Animal….

 

[aquaman67]

Thanks everyone for your advice.

The heaters are Eheim JAGER Trutemp Aquarium Heaters. They do have their own thermostat.

They are several years old so I’m going to replace them. I’m going to go to 150W heaters and keep the Inkbird on a timer too. I’ll lower it to one hour if the heaters keep up.

I like having redundant controls to keep the heaters from getting stuck on.

What if the temp probe malfunctions? Or falls out?

The controller offers it and I like using it.

 

[BeanAnimal]

There is no need to replace the heaters if they are keeping up.

Adjust the thermostats on the heaters to be a few degrees above the set point of the controller. Do this PHYSICALLY by feeling the "click" of the contact and/or watching the light on the heater... not by the number on the dial.

Part of your extended run times could be because the internal thermostats are hitting their set point and turning them off even though the inkbird is calling for heat.

The inkbird probe MUST be in the same compartment as the heaters. NEVER separate the temp probe and the heaters in different sump compartments or put the probe in the tank and heaters in the sump. You are asking for disaster.

Ditch the timer based alarm - it is useless.

Never use the heater's internal thermostat as a daily temperature control.... only use it as a failsafe set a few degress above the desired system temp (or at some maximum system temp)!

 

[workhz]

Btw, I do use the heaters internal thermostat as the control and the InkBird as the backup.

The internal thermostats do keep the temp pretty constant. Setting it up the traditional way and the less traditional way still requires 2 failures to cook a tank unless you’ve set the limits on either the heater or the InkBird way too high. I still prefer having the InkBird as the last defense vs the heater.

 

[BeanAnimal]

Btw, I do use the heaters internal thermostat as the control and the InkBird as the backup.

The internal thermostats do keep the temp pretty constant. Setting it up the traditional way and the less traditional way still requires 2 failures to cook a tank unless you’ve set the limits on either the heater or the InkBird way too high. I still prefer having the InkBird as the last defense vs the heater.

It needs to be setup the other way around. The vast majority of heater failures are due to the failure of the internal thermostat, they are absolute crap comprised of either bi-metal contacts and a spring or other "adjuster", or dirt cheap minimally spec'd solid state components (MOSFET, IGBT or SCR). In either case both the thermal cycling and arcing that happens during each activation wear them out.

That and just because the inkbird is calling for heat, how does it know if one or both heaters are actually running, or have hit their mark... It just assumes they are running based on ITS setpoint and what IT would be doing...

The way you have it setup, all the inkbird is doing is deciding if its 120V connection is ON or OFF based on the probe... and timing it (to no use). The heaters themselves can only run when the inkbird thinks they can run, but they can turn themselves off even though the inkbird is stills supplying them power.

Swap the logic around - let the inkbird do the control. Place the probe in the same chamber as both heaters, preferably just upstream of them. Set the thermostats as I described. The ideal place is in the input chamber of your sump where the heads will NEVER get submerged and the water height can never drop and expose the envelope.

You will be many times more fail-safe and the inkbird's alarms and reporting will actually represent what is happening.

 

[LiamPM]

Does seem liek a very long time to be continuously heating the water - Id understand if it was heating from zero but just to keep the temperature where it is they are on that long - Just seems very odd.

Have you checked both are working and actually producing heat?

Are the heaters internal thermostats set to a degree or two higher than the inkbird controller? Heater thermostats are fairly inaccurate in the grand scheme of things - Your inkbird might be turning the power on to the socket but your heater may be cutting that power if not - And not fully heating the water how it should.