Kessil

Heater issue

Dude! I posted that you can caibrate it on reply #4;)

So how do you know what to calibrate a heater to?

I was using two MCP9808 sensors for a pool solar project, and thought I might check by putting them in the tank.
I unfortunately don't remember the exact results.
But those sensors matched, and the Apex was disappointingly off.
Not worrisome-off, just surprised, but I think more than 0.2 deg.

I never tried boiling/freezing as calibration.

So are you sure you adjusted them the right way?
:)
 
With my Eheim/Jaegers, I see what my tank temp is and adjust the top of the heater so that the set temp matches actual temp.
I think @Vhuang168 ‘s point is how do you know what your tank temp actually is? Are you going of an apex probe, a secondary probe, a cooking thermometer? How do you know that that source is accurate? The NIST thermometer is supposed to be calibrated and tested to be true.

I’ve never bothered since I don’t think the actual temperature is that important. Even a difference of 2 degrees (which is what I would guess 99%+ of thermostats/probes are within) isn’t a problem. Say the thermometer shows 80 but it’s actually 82. 80 is where I start methods to cool the tank (evaporation, chiller,...). The corals can handle a true temp of 82. The opposite is true too.
 
if it has not already been stated
purchase a single stage ranco or aqualogic type thermostst
I DO NOT trust ANY of the thermostats of the submersible heaters...ebo, aqueon, marineland...NONE of them

if you can afford to be in the hobby, you can afford the controller
and ultimately, it will save the life of your investment
 
if it has not already been stated
purchase a single stage ranco or aqualogic type thermostst
I DO NOT trust ANY of the thermostats of the submersible heaters...ebo, aqueon, marineland...NONE of them

if you can afford to be in the hobby, you can afford the controller
and ultimately, it will save the life of your investment

I concur. As much as I love the neo-therm heaters, they are connected either to an Apex or Ranco.
 
It always surprise me how we trust some old-age myth about technology and don’t want to see that times changing. I came here with degree in electronics and see some controversy in external controller vs heater discussions. There are two types of control mechanism (controllers) and there are two types of switching devices that works completely different:

1) Mechanical bi-metal devices like old-style glass heaters - the relay is inside of glass heater, not exposed to aggressive saltwater environment but as any mechanical relay will stuck in open or closed position eventually.
2) Electronic heaters with mechanical relay ( i think eheim are electronic but sure). More precise than mechanical devices but has same problem - relay will stuck.
3) Electronic heaters with SSR - solid stay relays. Example is neotherm - the electronic side is isolated and thus protected from aggressive saltwater environment. Don’t stuck closed/opened. Has good precision.
4) External controllers - can have both types or switching - mechanical relay or SSR. Mechanical can stuck same way as embedded in heater. Compare to 2)3) it might have some disadvantage compare to heater-embedded electronics - it’s might not be designed to be placed in aggressive environment and if placed inside of the stand will be less reliable than one inside of heater. Has better precision than mechanical heater-based but might be same as electronic heaters.

My point is - if external controller has SSR relays and designed for aggressive environment it will be as reliable as neotherm - type of heater. Otherwise its same or even less reliable as good modern heater. There are also always quality concerns - is this particular heater/controller built with good quality control or simply ordered from some unknown factory in Asia and simply labeled later? I heard a lot of stories when apex controllers died - in theory it has all we need but how can we completely rely on those?
 
The trick to full safety:
1) Make sure heater element can never be stuck ON.
2) Have a controller that sends a max/min temperature warning.

FYI: Relays usually get stuck on when they fail. Welding themselves or broken spring.

To do #1:
Use an external controller, preferably a reputable one, for main control, set to 78 for example.
Set heater itself to a value slightly above external one, 79 for example.
It takes both to be ON for element to be active. Either can fail ON safely.

There is still risk if either fails off, but a slowly cooling tank is not that big of a deal.
 
Agree that it is important to recognize that different technologies for thermostats will have different accuracies and failure rates.

But since all failures are rare events, the real key is redundancy, so that when one fails there is a backup to prevent catastrophe and give us time to replace or fix the failure.

What I’m currently using is 2 Finnex titanium heaters without internal thermostats, each of which is enough to barely keep my tank temp up but not fry it. Each is controlled by a separate outlet on my Apex, and also has an InkBird controller set to a higher temp as failsafe. The Apex is set so that one heater is on most of the time and the other only rarely when the first can’t keep up. So there is minimal switching of any outlets and multiple redundancies.

The reasons I’m using the Apex as primary controller is I feel it is probably more reliable and also gives me nice data and configurable alarms to see when something isn’t right, like a component failure.

And so far I’m happy with the InkBird controllers. They also have a cooling option which would be nice if it were the primary, but I’m not using with this setup.
 
IMO: A solid state relay on a high current device like a heater does not make that much sense.
They consume a fair bit of power, so need a heat sink, or can die prematurely.
 
IMO: A solid state relay on a high current device like a heater does not make that much sense.
They consume a fair bit of power, so need a heat sink, or can die prematurely.

The SSR inside of the heater is submerged in the water so the heat is not an issue. For external controllers it might be a problem. And this is another point to say external controller MAY add another point of failure instead of increase of reliability.
 
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