Cobalt Heater with JBJ Controller

[Crabs McJones]

I believe I know the answer to this, but I'd like some reassurance.
Currently I'm running the JBJ TrueTemp Controller with a 300Watt titanium heater. The titanium heater has no controller or temperature sensor of it's own, its controlled solely on the JBJ. I just got a Cobalt Neo-Therm 300W heater for two reasons, firstly from the brstv investigates they're the least fluctuating, and second I want that internal sensor and control on the heater for added redundancy. So my question is I want the cobalt to control itself and use the JBJ controller as a fail safe. So I would set the cobalt to 78 and set the temperature on the jbj to slightly higher correct? Was thinking about setting the temp on the jbj to 80 so if the temp ever passes 81 it cuts power to the cobalt as the jbj allows for a +/- 1 degree swing.
Do I have this correct or is there another way to set it up.

 

[nautical_nathaniel]

You've got the right setup in mind, set the heater at the temp you want and set the controller slightly higher as a turn off point/fail safe

 

[joec]

First, the Cobalt heaters are less efficient than than Eheim, for example. Not all 300 watts, or whatever, produce the amount of heat apparently.

Your set up is theoretically correct, the controller should be set at the higher temp, assuming it more reliable than the heater, which the JBJ may or may not be..

For current set up, I just went with three Neotherm 100W heaters, no controller for my 53G. These supposedly according to Cobalt, cannot get stuck in the ON position. With the redundancy of three, if one dies, two will still keep my tank at 74 - 75 degrees, so I'm thinking a separate controller isn't necessary, I hope. LOL.

5 months and no issues....

 

[Crabs McJones]

First, the Cobalt heaters are less efficient than than Eheim, for example. Not all 300 watts, or whatever, produce the amount of heat apparently.

Your set up is theoretically correct, the controller should be set at the higher temp, assuming it more reliable than the heater, which the JBJ may or may not be..

For current set up, I just went with three Neotherm 100W heaters, no controller for my 53G. These supposedly according to Cobalt, cannot get stuck in the ON position. With the redundancy of three, if one dies, two will still keep my tank at 74 - 75 degrees, so I'm thinking a separate controller isn't necessary, I hope. LOL.

5 months and no issues....

300 watts is probably overkill for my system. I could probably get away with 150 watts, but I went with bigger. I went with cobalt more or less for their temperature range. They had the least fluctuation in temperature that I saw. Before with just the jbj controlling my heater there was a 2 degree swing every couple hours. And I'm hoping that this setup stops that and keeps it at a much more stable temp.

 

[joec]

300 watts is probably overkill for my system. I could probably get away with 150 watts, but I went with bigger. I went with cobalt more or less for their temperature range. They had the least fluctuation in temperature that I saw. Before with just the jbj controlling my heater there was a 2 degree swing every couple hours. And I'm hoping that this setup stops that and keeps it at a much more stable temp.

My temp with these doesn't budge. I like them a lot and I use Eheim on a each of two QT tanks.

Chewy.com often has good sales on the Neotherms.

The only concern I have at this point is how long will they last, but so far so good

 

[Crabs McJones]

Hooked up and seems to be running good. Thanks ya'll!

 

[Crabs McJones]

Another question for you guys. For some reason I cannot keep my tank cool even with the ac on. This has never been an issue before getting the cobalt heater. My question is, should I trust that my temp has always been low and the cobalt is actually bringing the water up to proper temp? The only thing I have to calibrate the jbj is a digital temperature gauge I bought at petsmart a couple years ago and I've adjusted the temp a couple of times so I'm not really sure what the value actually is now. My controller is showing 81 to 82 but the led readout on the cobalt is saying 78....should I purchase another thermostat to confirm?

 

[drtrash]

Yes thats a big swing

 

[Crabs McJones]

Yes thats a big swing

So do I trust that the cobalt is correct or do I trust the digital thermometer?

 

[Crabs McJones]

When brstv did their investigate they found that the cobalt was out of the box 78.5 degrees with a .05 degree swing. So I really want to trust it, but I just dont know. #reefsquad what do you guys think?

 

[Crabs McJones]

the cobalt says 78 and they're giving off heat, but the jbj and digital gauge says its 80

 

[drtrash]

Tough wisdom, but dont trust if you can verify, i would buy a thermometer cheap valid second opinion

 

[joec]

Buy a cheap glass thermometer, and do ice water test to see how far off it is real temp. You can then use it to figure out your actual water temp, and you'll know whether Cobalt or or your controller is off and approx by how much

 

[Crabs McJones]

Buy a cheap glass thermometer, and do ice water test to see how far off it is real temp. You can then use it to figure out your actual water temp, and you'll know whether Cobalt or or your controller is off and approx by how much

Could you go further into the ice water test? Never heard that one

 

[joec]

You tube has many other videos on this. Ice water is 32 degrees. Follow the procedure closely. Almost all ice should fill the container. Give the water time to cool down, I even stick it in the freezer for a bit and then test the liquid water temp with thermometer

Use the cheap glass aquarium thermometer, after you figure out its accuracy with the ice water test, you can calibrate your tank temp with it. It will tell you real temp, and how far off the Cobalt and or the controller may be

 

[Larry L]

First, the Cobalt heaters are less efficient than than Eheim, for example. Not all 300 watts, or whatever, produce the amount of heat apparently.

I've seen this mentioned a few times but I'm having trouble believing it. If both heaters draw 300 watts, and everything is submerged except the plug and cord, then there's no place for that power to go except to be dissipated as heat in the water. So either the Cobalt's cord is getting hot and dissipating heat to the air, or it is actually drawing less wattage than the Eheim. Has anyone plugged one of each into a Kill-a-Watt or similar device to see how much power they draw?

My suspicion is that this is based on Eheim recommending smaller wattage heaters for the same size water volume as Cobalt, which doesn't have anything to do with how efficient they are and is just the manufacturer's guess at "typical" conditions (including e.g. differences between room air temp and tank temp, how much heat is lost from the tank and how fast, etc.).

 

[joec]

It even seems to be suggested in their ratings:


Cobalt Neotherm maximum tank size

25W 6 Gallons
50W 12 Gallons
75W 20 Gallons
100W 29 Gallons
150W 40 Gallons
300W 75 Gallons

Eheim

50 7-16 gallons 9"
75 16-26 gallons 10"
100 26-40 gallons 12"
125 40-53 gallons 12"
150 53-79 gallons 13"
200 79-106 gallons 15"
250 106-159 gallons 17"
300 159-264 gallons

 

[Crabs McJones]

You tube has many other videos on this. Ice water is 32 degrees. Follow the procedure closely. Almost all ice should fill the container. Give the water time to cool down, I even stick it in the freezer for a bit and then test the liquid water temp with thermometer

Use the cheap glass aquarium thermometer, after you figure out its accuracy with the ice water test, you can calibrate your tank temp with it. It will tell you real temp, and how far off the Cobalt and or the controller may be

Thanks! So I just ran the test, and from what I can tell, it should read 0°c or 32°F when I do this test my digital temperature probe reads 31.6°f or -0.2°C. So I need to adjust for .4°F difference.

 

[joec]

Yep

 

[Crabs McJones]

Yep

So with that being said I have my cobalt set to 78ﾟ but it's actually 80 in theory if I set it to 76 that should drop it to 78 if it's 2ﾟ off. I'll try it and see what happens.