Using 2 heaters

tablesalt

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Were it me I'd get a stand alone 300W heater with it's own thermostat, and set it to about 2 degrees cooler than what your current heater is set at. I would keep it completely separate from the controller. This will ensure that you do not have "dueling heaters". The backup will only turn on if your primary fails and the likelihood of both of them being stuck on at the same time is extremely small. I agree that the primary 500W may be a little strong/risky for that tank.
 

T_Dawg

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I use two heaters plugged into a Jehm Co. temperature controller. The Jehm Co. is plugged into the powerbar of my Apex unit. It is overly redundant. The temps on and off are controlled by the Jehm Co. set to a single degree fluctuation (78-79), but then additionally controlled by the Apex which is set to a two degree fluctuation (half a degree higher and lower than the Jehm setting = 77.5-79.5), and finally the heaters themselves are set one half degree higher than the Apex (80). My temps have been stable to one degree for over two years now. Should the Apex fail the Jehm controller takes over and vice versa, should those both fail then the heaters control should take over. I have had a single heater failure and the temperature stayed rock solid. I noticed the light did not come on in the heater one day while cleaning and then figured out that it was broken and easily swapped it out.
 

Clownfish2

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My display plus sump totals 140 gallons and I have 300 watts of heater. That equates to 2.14 watts per gallon. The coldest my house gets is 64 in the winter season if my HVAC continues to operate flawlessly.

One situation where having a heater in the display tank is a good idea is if you are out of town for days and your return pump fails. In the warm season....no big deal. But in winter, my house may be 64. Before leaving town, I string in a heater into the display as a backup if my return pump stops.
 

NY_Caveman

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There really is no need to run the heaters at different temperatures. Run them the same. BTUs added to the water are BTUs added to the water. Also is not necessary to run a heater separate in your DT. One benefit of a sump is to hide equipment. Why would you want a big ugly heater in your DT when it can go in the sump?

I would also bite the bullet and get a full-blown controller for the heater. Perhaps it is time for the Apex. When heaters fail the usually fail in the on position.

I think it was @randyBRS who said he liked to use two fully rated heaters on a system set 1 degree apart (EDIT: corrected below, it was Ryan, not Randy). I found his explanation quite interesting. Paraphrasing: since heaters are known to fail, this gives an immediate backup when the primary heater fails. That backup is essentially a new heater. Running them at the same temperature could result in both failing near each other over the course of time considering equal wear on the same heaters.

No matter what you decide, controllers and temperature, I think you are definitely right to use two heaters. For my small system of 26 gallons water volume I am using two 75 Watt Cobalt Neo-Therm heaters and have an Eheim 100 Watt as a backup.
 
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ReeferBob

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I think it was @randyBRS who said he liked to use two fully rated heaters on a system set 1 degree apart. I found his explanation quite interesting. Paraphrasing: since heaters are known to fail, this gives an immediate backup when the primary heater fails. That backup is essentially a new heater. Running them at the same temperature could result in both failing near each other over the course of time considering equal wear on the same heaters.

No matter what you decide, controllers and temperature, I think you are definitely right to use two heaters. For my small system of 26 gallons water volume I am using two 75 Watt Cobalt Neo-Therm heaters and have an Eheim 100 Watt as a backup.

I would dump the Cobalt now before (not if) it fails. They are the worst heater on the market. They have also been known to fail explosively leaving glass in your tank. They seriously should be forced to recall them all.
 

NY_Caveman

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Hmm... Their Accu-Therm heaters are glass, but the Neo-Therms (at almost three times the price) have a casing that Cobalt claims is shatterproof.

Accu-Therm
042E133C-83B8-44DB-B7F5-3FE9DDA8F4FD.jpeg


Neo-Therm
F015C2E5-6988-4066-A975-9724CCBC7CFD.jpeg

(photos borrowed from BRS)

For my small system, the Neo-Therms are desireable because they are small enough to fit, one each, in the dual, small compartments in the back of a JBJ Rimless 30.
 
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NY_Caveman

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Also, my mistake above. It was @Ryanbrs Who recommended the dual heaters at different temperatures:

“So there are a lot of approaches, and peoples opinions differ, but my opinion is you should have one heater which is fully capable of heating your tank on its own to ~78 degrees. If you have a large tank it might be a pair of heaters. This heater or heaters will be responsible for cycling on and off thousands of times a day and likely millions of times a year to maintain the tank temperature.

Now, this heater will fail, could be 6 months could be 36 months, but it will very often be between 12 and 24 months. That's why we add redundancy with a backup heater. I think it should be the same size and very similar solution to the primary and it should be set to ~77 degrees which is one degree lower. This means the heater will basically never be used and hopefully perform like new when you need it.

Now a lot of us have taken a different approach which is two heaters set to the same temp designed to limit negative effects a failure meaning if one fails on or off the tank won't heat up as fast or drop as low. This is certainly better than a single point of failure with just one heater but really a "less worse" or partial solution. It's also less likely to work when you need it because both heaters are cycling that same million(s) of times a year and likely to fail around the same time. If I did it this way, I might use different brands of heaters to reduce that risk.

In either case, a temperature controller is an absolute must-have for anyone who uses a heater and wants to have their tank last more than a couple years. There are not many things I would say are 100% necessary, but this is one of them. The ink bird is $39 and there just isn't a reason not to use one other than I literally don't have the $39. If that's the case so be it but that should be the only reason.There are of course more expensive andcapable solutions like the reefkeeper and apex. At this point, there isn't a universe where I wouldn't personally use one of those twooptions because I have a lot invested in my tanks. Most often I use the apex just because it actually lets me know "in real time" when something failed.

As to cheap heaters verses the Neotherm? Well, it is 3 x the cost so I would only spend that to achieve a specific goal. I would also only use it on a tank that has the potential to benefit from that. In this case that could be a SPS tank which almost always benefits from every effort put towards stability. The goal would be accuracy, precision and redundnacy. In this case, I would actually use the internal thermostat on the heater to control the tanks temperature and the aquarium or temp controller to back it up. The benefit here is the we don't have to power cycle the entire heater millions of times a year which is certainly not good for it.

Hope that helps :) , I got a bit more on this in this weeks video update.”

https://www.reef2reef.com/threads/tank-trials-ultra-low-maintenance-tanks-brstv-investigates.341149/page-17#post-4316538
 

FlyinBryan

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In my 405g system I have 5 or 6 heaters all set to the exact same temp. I only use 150w max size heaters. I’ve had heaters fail in the on position (freshwater) and cooked all my fish. Splitting it up prevents major disasters in either direction. A 500w heater, that’s a lot of power especially for a 90g display. Not being critical, I personally would break that up into several heaters.
 

ReeferBob

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I must disagree with the logic used to justify setting different temps on redundant heaters. It is severely flawed. What it says is to put a new heater in a tank of saltwater and let it sit there off for 2 years and then expect it to work when called upon. I think this is more likely to produce unpredictable results than running it in unison with another heater "exercising" it. There is no set lifespan for heaters. I have had heaters last well over 10 years and still work today. If you use 2 heaters and are worried that they will die at the same time I would suggest you get 2 different brands or at least models. My experience is the more complex they are (fancy LCD screens, etc) the quicker they fail. And you could use the same argument for not running the heaters at the same temp as for running them at the same temp! That is, they will last twice as long due to needing 1/2 as many on/off cycles. And if you are really concerned, you could replace your heaters every 2 years as part of your maintenance.

Since our controllers will prevent an overheat situation, if you are concerned about premature failure, you could always add an alarm for under temperature situations. My ReefKeeper can do this out of the box as I think most complex controllers can. I did have a heater fail once in the closed position and I only knew when I noticed my clown acting a bit lethargic. The tank had dropped to around 72. I put in a spare heater and no lasting effects for the tank. The other failure was with a Cobalt heater. One cracked and one failed in the on position but my controller shut it off. I found out when I noticed it looked discolored and did some testing and realized its internal thermostat was no longer working. Reading up on Cobalt it quickly became evident that this is a trash product.
 

mcarroll

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Why would you want a big ugly heater in your DT when it can go in the sump?

Waste of heat between the sump and display....I had to keep my sump REALLY warm for it to heat both displays.

Right-sized heaters aren't that big or really that hard to hide. ;)

(I think I already posted earlier with my other details.)
 

NY_Caveman

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For power, it is like an extension cable, but splits and has two outlets. So you can plug two heaters into one outlet. There are other kinds of connections other than power than can use a Y-cable or Y-splitter.
 

NY_Caveman

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I must disagree with the logic used to justify setting different temps on redundant heaters. It is severely flawed. What it says is to put a new heater in a tank of saltwater and let it sit there off for 2 years and then expect it to work when called upon. I think this is more likely to produce unpredictable results than running it in unison with another heater "exercising" it. There is no set lifespan for heaters. I have had heaters last well over 10 years and still work today. If you use 2 heaters and are worried that they will die at the same time I would suggest you get 2 different brands or at least models. My experience is the more complex they are (fancy LCD screens, etc) the quicker they fail. And you could use the same argument for not running the heaters at the same temp as for running them at the same temp! That is, they will last twice as long due to needing 1/2 as many on/off cycles. And if you are really concerned, you could replace your heaters every 2 years as part of your maintenance.

Since our controllers will prevent an overheat situation, if you are concerned about premature failure, you could always add an alarm for under temperature situations. My ReefKeeper can do this out of the box as I think most complex controllers can. I did have a heater fail once in the closed position and I only knew when I noticed my clown acting a bit lethargic. The tank had dropped to around 72. I put in a spare heater and no lasting effects for the tank. The other failure was with a Cobalt heater. One cracked and one failed in the on position but my controller shut it off. I found out when I noticed it looked discolored and did some testing and realized its internal thermostat was no longer working. Reading up on Cobalt it quickly became evident that this is a trash product.

Nice. I was offering it as an option but I should say I am have not decided yet if I will do this in my own aquarium so I appreciate your opinion.

For me, I have an Ink Bird Temperature Controller ITC-308 I will use also to regulate the heaters and help avoid a “stuck on” failure. The Ink Bird has a heater and a chiller outlet and I will use a y-splitter to plug in the two heaters. If needed I will put a fan on the tank and use that in the chiller outlet.

EDIT: the controller was $35 which is pretty cheap to help minimize the catastrophe of a heater failure.
 
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oneilwiz

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Happy Friday reefers,

Great write up here, very useful thread. I am currently in the market of replacing or preparing to replace my two Aqueon Heater ( no issues with them). I usually try to replace after two years. I had a disaster where my tank crashed with only two fishes surviving. Long story short, went away on vacation in February for two weeks. I got no alerts from apex since my heaters were in the sump along with the temp probe. When I got back the sump ran out of water, return pump ran dry and died.

I could have avoided this by using a bigger RO reservoir along with a camera and an additional temp probe in the DT overflow box. Also had the Neo Cobalt on my nano and that thing failed after only 4 months.


Happy Reefing everyone,

https://www.instagram.com/wizreef/
 

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