# Using 2 Heaters or 1 Heater on a 60 Gallon



## Ensorcelled

Hi everyone! First post here as I've mainly lurked for a good amount of years and recently decided to join the forum.

Anyway, I've got a question. After searching through the countless threads on heaters and whatnot, I generally see that people use and recommend 2 heaters instead of 1 for fail-safe purposes. Now I've been in the aquarium hobby for 5+ years and have always used 1 per tank and always had no problems.

I recently obtained a 60 Gallon and my 2 month old 300-Watt visitherm is already failing due to condensation. I have been using the 5 watts per gallon rule for all these years however, I just purchased a single Fluval 200-Watt E Heater and wanted to know if 1 heater will be enough in terms of even heat distribution. The tank is circulated by a Fluval C4, Aquaclear 500, and 2 Maxi Jet 600's in each corner of the tank. Plenty of water circulation and 1 heater has never been a problem for me but I guess I just need reassurance on the whole subject of even heat distribution.


----------



## rgr4475

I would say use the 1 heater especially if your tank is indoors and climate controlled. You want the lowest possible wattage that keeps your temp where you want it. That so incase the heater breaks and gets stuck on, it's not powerful enough to boil your fish. In my 180 I have 2 heaters at a total of 450w. So in a 60 gallon, one should be plenty.


----------



## prov356

> I generally see that people use and recommend 2 heaters instead of 1 for fail-safe purposes. Now I've been in the aquarium hobby for 5+ years and have always used 1 per tank and always had no problems.


Me too, and I don't subscribe to the two heater idea at all. Just size one properly. The idea with two is that if one sticks on, it won't be strong enough to cook your fish. Also, the idea is that if it's not strong enough to cook your fish, it's not strong enough to heat adequately, so you need two. No truth to that at all. Get a heater that can take the tank temp to no higher than 86-88. Then a) it'll adequately heat the tank, and b) if it sticks on, it won't cook your fish. The other idea is that if one heater fails completely, then the tank won't get cold and kill your fish. The problem with this idea is that most people keep their homes at 70-72. That temp generally does no harm to fish. The danger is in overheating, not underheating. So, while true, I've never found it to be high risk enough to keep two live heaters going in a tank. Besides, I've got 20+ tanks.



> I have been using the 5 watts per gallon rule for all these years


Old rule, way too much wattage, and will kill your fish quickly if it sticks on. Tank size* and room temp *will determine wattage needed. You can't properly size a heater by tank size alone.



> I just purchased a single Fluval 200-Watt E Heater and wanted to know if 1 heater will be enough in terms of even heat distribution. The tank is circulated by a Fluval C4, Aquaclear 500, and 2 Maxi Jet 600's in each corner of the tank. Plenty of water circulation and 1 heater has never been a problem for me but I guess I just need reassurance on the whole subject of even heat distribution.


Yes, absolutely one heater is enough. The only time I'd consider two is if I had a very long tank, and then I'd put them on one controller with a temp sensor in between. (Of course then I"d be running a sump, so would only need one in the sump) Multiple heaters each on their own controller in one tank is not how they were designed to work. These heaters are designed to work within a range. So, if set at 78, then it'll kick on at 77.5, go up to 78.5, then turn off, for example. Unless you get them set precisely the same (which you never will) one may never come on at all. Or they may turn on and off erratically as each is affectec by the other.

Stick with your one heater plan, it's a good one IMO, and has served me well for years. Just size that one heater properly.


----------



## the blur

2 heaters for sure, 2 filters too. it's called redundancy, and fail safe. how many people keep their house at 72..... no one I know, unless your visting a nursing home. most houses are 68 during the winter when occupied, and lower during work hours when no one is home.

another nice thing about 2 smaller heaters. you unplug one during the summer.

I just had a visitherm fail. the tank got to 82-83. if that was a bigger heater, they would have fried.


----------



## prov356

> 2 heaters for sure, 2 filters too. it's called redundancy, and fail safe.


Fish do fine at a much wider temp range than we give them credit for. It's just not necessary to worry about low 70's. And it takes a long, long time for temps to drop to air temp. There's no fail safe measures needed. No harm (as long as they're properly sized which many don't do, they oversize even with two), but no need. I understand redundancy, and you don't need it with heaters, filters yes, but you can't compare heaters to filters. Filters are mission critical, heaters no. And I'd really like to know how you know what temp everyone keeps their houses at? :wink:



> another nice thing about 2 smaller heaters. you unplug one during the summer.


If less heat is needed during the summer, one will work less without unplugging it. You save on electricity just the same.



> I just had a visitherm fail. the tank got to 82-83. if that was a bigger heater, they would have fried.


You're missing the point. You don't go with one massive heater if you only have one. You go with one properly sized heater. The one that took it to 82-83 is enough to heat the tank by iteslf, yes? So, why the need for two? Use the one that took it to 82-83, then fish don't fry.

Sorry, but this new '2 heaters are a good thing' phenomenon that seems to be sweeping CF is one of my pet peeves. I don't know how it got started, but it's just not necessary. Any harm? No but neither is there a need. Buy a properly sized heater and check your fish, filters, temp, etc at least once each day as you should be and all will be fine. But if it gives you peace of mind, then get two.


----------



## the blur

we're not talking about saving electricity. who ever mentioned that??????
I'm a redundacy engineer for NASA; all your arguments are not valid for a number of reasons.

your heater can fail in 2 modes; open or closed. if it fails open, you have no heat. I have 50% heat. probably enough to keep my tank warm.... depending on the heat loss of the tank. certainly enough heat to keep my fish alive for the week I am traveling on business.

if your heater fails closed you have fried fish, or at least in the danger zone. me, I have a very slow steady raise of temperature that will happen over a few days, or even longer. I travel for a week, my tanks are fine without supervision.

another benefit with 2 heaters. more stable tempertures. as I said during the summer, pull 1 heater out. the remaining heater will stay on longer. not cycling frequently. your 1 heater is cycling twice as often as my 2 heaters.

another benefit, longer heater life with 2 heaters... bacically because they are not cycling as your one heater.


----------



## the blur

and you mention a properly sized heater.... that is a misnomer. properly sizing it is just an estimation. your heat loss is constantly changing. winter or summer? is the tank near a window, or in the basement? is sun shining on the tank? or is the A/C blowing on the tank? what lighting do you have?

if your heater was sized exactly, it would be on 100% of the time, and the tank temperature would never change. you would match it to the heat loss..... which we know always changes.

so because of all that, we take a good estimation on heater sizing. then I downsize by 25%. so technically while I am running 2 heaters, I am not downsizing by half. I'll run 2) 75's rather than 1) 100. or I'll run a 50 and a 75, while your running 1) 100. my method is far superior, and offers 1 level of redundancy.


----------



## rgr4475

Wow, you really come off full of yourself. So because your a NASA engineer that makes you an expert on fish tank heaters? And your method is far superior? C'mon. If spending double the amount I would normally spend to accomplish the same thing, how is that superior? If my one heater fails (Either stuck on or not turning on at all) and does not harm my fish then how is your method superior? It doesn't make it wrong, just another way of doing things. And everyone of Prov356's arguments are completely valid. Congrats on your job at NASA but it doesn't make you right and everyone wrong.


----------



## prov356

> we're not talking about saving electricity. who ever mentioned that??????


That was a guess, I couldn't figure out why else unplugging one in the summer would be of any benefit.



> I'm a redundacy engineer for NASA


I'm not. But, I've tested aquarium heaters in my tanks quite a bit, so feel qualified to speak on the subject anyway.



> if it fails open, you have no heat


Not true, the water has and holds heat and will continue to hold heat long enough to discover the problem and deal with it IME. It takes a long, long time for the tank temp to drop, it really does. Particularly a large tank. Tank size matters of course, but I'm assuming we're talking large tanks and not about putting two heaters in 20 longs.



> certainly enough heat to keep my fish alive for the week I am traveling on business


Introduced a new element to support your side mid debate?  If someone takes frequent extended trips, and has no one to check on their tanks, then it could make sense to do this.



> if your heater fails closed you have fried fish, or at least in the danger zone


No, I don't. Again, properly size it so it won't overheat the tank.



> during the summer, pull 1 heater out. the remaining heater will stay on longer. not cycling frequently. your 1 heater is cycling twice as often as my 2 heaters.


No because my heater is the same as each of your two. My one works the same as your one. Your mistaken in saying that one of your heaters isn't enough to heat your tank alone. If it took the tank to 82-83 and wouldn't have gone much higher, then it's perfectly sized like mine and will behave like mine and cycle on and off like mine.



> another benefit, longer heater life with 2 heaters... bacically because they are not cycling as your one heater.


Not true again. One proplerly sized heater will take a long time to raise the tank to it's upper 'off' limit. I've tested this, really, I'm not making this up. Depends on the tank size, room temp, etc, but in my case with my 180, it was a very slow on/off cycle. It surprised me actually.

Check out the info on the bottom of this web page. It explains why two heaters on their own controllers may behave erratically.



> and you mention a properly sized heater.... that is a misnomer. properly sizing it is just an estimation


Depends how you approach it. It doesn't have to be an estimation. Add a heater when first setting up and no fish. Crank it up all the way. If it takes the temp to mid to upper 80's, then it's properly sized. Room temp can vary, but you're in a range, so seasonal fluctuations aren't a big deal. And if it gets warmer than set temp in the room, the heater isn't coming on any more anyway.



> if your heater was sized exactly, it would be on 100% of the time


The above example of a properly sized heater would turn off at set temp just like any other.



> so because of all that, we take a good estimation on heater sizing. then I downsize by 25%. so technically while I am running 2 heaters, I am not downsizing by half. I'll run 2) 75's rather than 1) 100. or I'll run a 50 and a 75, while your running 1) 100.


With your method you may actually be running two heater capable of overheating the tank doubling the odds of disaster. You're guestimating, I'm not.



> my method is far superior


I think that's still up for debate. You seem to be getting your feathers ruffled a bit. I'm just trying to openly and fairly debate the question. That's all.


----------



## GTZ

I run two, but I have one set ~5*C lower, it never comes on and will only ever come on if the other fails open. Baseboard heating, tank's in the basement and the heat is only ever on at night for 3-4 hours, otherwise it's a toasty 15-20*C.


----------



## M&amp;S

GTZ said:


> I run two, but I have one set ~5*C lower, it never comes on and will only ever come on if the other fails open. Baseboard heating, tank's in the basement and the heat is only ever on at night for 3-4 hours, otherwise it's a toasty 15-20*C.


Me too, I run two heaters, one set just below the other (only just below, so when I do a water change the other one comes in as well, my check that it is working every so often). I don't see the point in keeping my spare in the cupboard, it may as well be in the tank. I also leave my fish tank unattended when away. Our house sits at about 46F overnight and in the morning  .

My small tanks just run one heater, but actually the temepratures fall so quickly in these when the heater is off that two _would_ be a good idea in these (based on one failing when I'm away scenario).

But then I only run one filter per tank so...whatcha gonna do :lol:


----------



## the blur

that's another valid point. I don't need to keep a spare heater; nor do I run out to the pet shop when 1 heater fails. A spare heater is already in place, and I can get another one when ever.


----------



## prov356

GTZ said:


> I run two, but I have one set ~5*C lower, it never comes on and will only ever come on if the other fails open. Baseboard heating, tank's in the basement and the heat is only ever on at night for 3-4 hours, otherwise it's a toasty 15-20*C.


That's a much better strategy, but very different from what's being done out there commonly, and what's even being suggested in this thread. People are runnning two heaters simultaneously that both have the potential to kill their fish. I've seen the threads over and over lately. And recommending others do the same with the idea that somehow it provides more of a safety factor. Just the opposite. You've got a plan that makes sense, GTZ, and a very valid reason for doing so. Most don't. Adding two heaters set at 78 to one tank just is not a good idea unless you are absolutely certain that each one does not have the capacity to overheat the tank. But again, most people oversize thinking it's safer to make sure they have heat, when actually the opposite is true. I just encourage everyone using two heaters to think this through and have a plan that makes sense.


----------



## the blur

It's basically impossible to have 2 heaters set at the exact point. you think you do, you can try, but they are always different. 1 will always come on first, and they flip flop back and forth.


----------



## prov356

the blur said:


> It's basically impossible to have 2 heaters set at the exact point. you think you do, you can try, but they are always different. 1 will always come on first, and they flip flop back and forth.


That I can agree with. It can cause them to behave erratically. And does this frequent on/off actually encourage premature failure?


----------



## the blur

it doesn't cause them to behave erratically because they are placed on opposite ends of the tank.

Remember, a heater is an electro mechanical device. it's not "if it will fail", it is "when will it fail". they all will fail eventually. you can't maintain them because they are sealed units. So there is nothing you can do to prevent failure. it's going to happen.

and when it happens to a 1 heater tank, your running to the store for a new heater, (if the store is open), then your calibrating it under stress and adverse conditions.

while I simply unplug the failed heater, and feed my fish until the next day.


----------



## zimmy

> and when it happens to a 1 heater tank, your running to the store for a new heater, (if the store is open), then your calibrating it under stress and adverse conditions.


I could (and in fact do) have some extra heaters laying around. It wouldn't be that stress inducing to pull one out and set it up in the tank if the need arose.


----------



## Ensorcelled

Well... I didn't mean for this thread to turn sour over the whole discussion. I guess you could say I'm looking for the pro's and cons of using 1 as opposed to 2 in a tank. Like I said before, I realize there are tons of threads and other discussions on it but it's nice to have the reassurance on "your" setup.

Regardless, I still believe 1 heater in each tank setup is all you need. 2 Heaters for "fail safe" thoughts on the intended setup with the right reasons can be acceptable. I just personally don't see the reasons to have 2 instead of 1 being THAT much safer/better. Not to mention in my case the cost of 2 Fluval E heaters being pretty pricey.

Just my .2 cents


----------



## Ensorcelled

zimmy said:


> and when it happens to a 1 heater tank, your running to the store for a new heater, (if the store is open), then your calibrating it under stress and adverse conditions.
> 
> 
> 
> I could (and in fact do) have some extra heaters laying around. It wouldn't be that stress inducing to pull one out and set it up in the tank if the need arose.
Click to expand...

Agreed. I've had heaters completely fail on me before during hours when stores aren't open. The stress induced onto the fish is really negligible.


----------



## punman

Fish are more likley to die within a day with a heater stuck on than off.
With two heaters you are doubling the chance that a heater will fail and be stuck "on".
If I woke up one morning and found the temp at 70F I'd know the heater failed and pull out a spare that I keep on hand.
If I woke up one morning and found the temp at 95F I'd know the heater failed and pull out a bunch of dead fish.


----------



## prov356

> Well... I didn't mean for this thread to turn sour over the whole discussion.


I think it's been a good discussion and one that was long overdue. It'd be boring here if we all agreed with each other all the time.



> Fish are more likley to die within a day with a heater stuck on than off.
> With two heaters you are doubling the chance that a heater will fail and be stuck "on".
> If I woke up one morning and found the temp at 70F I'd know the heater failed and pull out a spare that I keep on hand.
> If I woke up one morning and found the temp at 95F I'd know the heater failed and pull out a bunch of dead fish.


Good summary.


----------



## the blur

prov356 said:


> Well... I didn't mean for this thread to turn sour over the whole discussion.
> 
> 
> 
> I think it's been a good discussion and one that was long overdue. It'd be boring here if we all agreed with each other all the time.
> 
> 
> 
> 
> Fish are more likley to die within a day with a heater stuck on than off.
> With two heaters you are doubling the chance that a heater will fail and be stuck "on".
> If I woke up one morning and found the temp at 70F I'd know the heater failed and pull out a spare that I keep on hand.
> If I woke up one morning and found the temp at 95F I'd know the heater failed and pull out a bunch of dead fish.
> 
> Click to expand...
> 
> Good summary.
Click to expand...

How is that a good summary ? HE obviously missed the entire point of using 2 SMALLER heaters. my tank will NEVER get to 95 with a stuck on heater, because the heater is UNDERSIZED.


----------



## Ensorcelled

Pretty sure hes implying that if both heaters decided to fail at presumably the same time it would be like having 1 heater fail etc...

I could be reading that wrong, /shrug I'm zombie mode from my night shift :zz:


----------



## prov356

> How is that a good summary ?


Seems you're just being argumentative now, blur, and taking things personally. It's a good summary of what people should keep in mind when considering heaters.


----------



## the blur

not taking it personally at all. Who cares, I will never meet you face to face.
he and you obviously missed the entire point.

if you have (2) 75 watt heaters, in a 30 gallon tank, and 1 sticks on. your tank is not going to 95 degree's in a short period of time. It may after a week or so depending on the conditions.

let's forget the whole thing, since it's not sinking in..


----------



## dotbomb

For all this redundancy you still have a single point of failure for the heater off position when you are gone for a week or more. Unless of course you run two dedicated electrical circuits to where your tank is and plug one heater into each circuit.

At some point you have to make a decision about how practical redundancy is. I'd rather own less equipment personally and get a heater that isn't going to cook my fish in the stuck on position.

I believe this is a sound engineering decision for me since either way my heater fails I don't end up with dead fish and I've got less equipment to maintain. I live in So Cal so my ambient temp is never going to fall enough to kill my fish.

Cost of ownership should be considered as well if you are doing a complete analysis.


----------



## rgr4475

the blur said:


> not taking it personally at all. Who cares, I will never meet you face to face.
> he and you obviously missed the entire point.
> 
> if you have (2) 75 watt heaters, in a 30 gallon tank, and 1 sticks on. your tank is not going to 95 degree's in a short period of time. It may after a week or so depending on the conditions.
> 
> let's forget the whole thing, since it's not sinking in..


You are taking it personally because god forbid someone is disagreeing with you. Don't get your panties in such a bunch over a heater. Accept there are more options then yours.


----------



## the blur

all this redundancy, yes, I have 1 heater plugged into an APC backup.
the heater you keep describing "that won't cook your fish", will not heat my basement fish tank on a cold night. or it won't heat my fish tank should I leave on vacation and lower the heat in the house.



dotbomb said:


> For all this redundancy you still have a single point of failure for the heater off position when you are gone for a week or more. Unless of course you run two dedicated electrical circuits to where your tank is and plug one heater into each circuit.
> 
> At some point you have to make a decision about how practical redundancy is. I'd rather own less equipment personally and get a heater that isn't going to cook my fish in the stuck on position.
> 
> I believe this is a sound engineering decision for me since either way my heater fails I don't end up with dead fish and I've got less equipment to maintain. I live in So Cal so my ambient temp is never going to fall enough to kill my fish.
> 
> Cost of ownership should be considered as well if you are doing a complete analysis.


----------



## prov356

Ok, well I think we've said all that can be said here, and hopefully it'll give everyone some food for thought. Thanks all for your contributions.


----------

