Two heaters vs. One heater per tank

Q&A about aquarium maintenance

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janiel
Posts: 10
Joined: Sat Jul 05, 2008 7:18 pm

Two heaters vs. One heater per tank

Post by janiel »

Hi Pam!

I have been researching the benefits of having one heater or two heaters in my 75 gallon. Again, I don't know why I am so confused!!! I'm probably missing some vital information; hopefully you can help me once again! :)

The obvious benefits to having two heaters seem to be: 1) it allows for placement at opposite ends for even heating, and 2) if one heater fails, the water won't get icy as the functioning heater will mitigate the temperature drop. However, I am in So Cal and I only need to warm things up by 5-10 degrees so I actually have the opposite fear that if the thermostat gets stuck, all will die if not caught in time. I had this happen several years ago, which killed off all of my mbuna except my two smallest- the Snow Whites. (The heartbreak kept me from getting others, but the endearing (and prolific!!!) Snow Whites have done a good job at comforting me! lol!) Anyway, I am most concerned with a faulty heater killing my fish again by either cooking them or driving all the oxygen out of the water so I have a few questions in my search for the (almost)perfect heater arrangement.

1) If I use two heaters and one gets stuck on, will this be less likely to create lethal conditions? I haven't found much online about this. I'm sure there has to be data somewhere, but I am not finding it!

I've found several resources that mention using one 300W, or two 200W or 250W heaters in a 75. I am trying to consider worst case scenarios. Certainly, two 200W stuck on would be the worst, but I hope that a double failure at exactly the same time is improbable and unlikely to happen. But will one stuck 200W running with a normally functioning 200W still be likely to kill the fish? Would it be worse than a single, stuck 300W heater? Is there anything else I can do? If I use only one 200W heater, or two 100W heaters, will that overwork the heater(s) and cause more problems and malfunctions? I suppose I could even use multiple 50W heaters, so if one fails and stays on, it is hopefully too weak to completely cook everyone, but that is pretty unseemly...


2) I began using Marineland stealth heaters based on a few positive opinions (and my misunderstanding of the term "auto shutoff" on their packaging :? ) but recently I've found a number of reviews that mention precisely the problem that concerns me. I am looking to replace all of my heaters with Rena smart heaters. Is there another reliable brand that I should look into? Ebo Jagers have some mixed reviews, as do Eheim Jagers though they also seem to be popular.

3) I intend to put a thermometer with an alarm on the 75 as soon as it comes in the mail. Unfortunately, the alarm will only help if someone is home. Do you know of something that can cut the power to the heater if the water overheats?

As you can probably tell, I have a lot of anxiety over this issue! I know I sound neurotic, :oops: but I just want to make the best choices for them. Now that I've read more reviews on the stealth, I have such fears again!

My fishies and I ***Thank you*** for your help in sorting through all of this!
Pam Chin
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Re: Two heaters vs. One heater per tank

Post by Pam Chin »

Hi Janiel,

I am very impressed with your research, and you have brought up many valid points. So lets discuss this a little further and sort out what is applicable to you.

I always approach this with the fish in mind first. You are working with cichlids from Lake Malawi and they do best at about 76 Degrees F. You live in mild to hot climate and you have a 75 gal tank and I assume you have central heating and air conditioning. Now if you were working with Discus and lived in Fargo North Dakota my answer would be totally different. Lake Malawi cichlids do not do well in higher temperatures, it increases aggression, shortens their life span, compromises your water conditions, and you have less oxygen in the water.

The main reason you want a heater is to stabilize the temperature in your tank, since a swing in temps can cause issues; ich, stress, etc. I would buy a 150 Watt heater, and call it good. There are some hobbyists that like to have two heaters incase one fails, but they are more then likely in colder area, your worst scenario is the tank would go down to the temperature you keep your house, and that would take some time. The other draw back to two heaters is two plugs are needed. When its summer, you may want to unplug your heater all together, if the temp swing is 5 degrees in that size of a tank, I wouldn't worry about it. I unplug mine, and I am way north of you.

I don't think anyone can guarantee that their heater won't stick, the minute you see a heater doing anything out of the ordinary you should replace it. Because that is your first clue that it could stick at any time. I really can't recommend a brand, I have probably used just about every brand at one time or another, stay away from the cheaper ones. Getting a temp alarm will hopefully decrease your anxiety. Also if you have a lot of powered equipment running your filters, it also heats your water, sometimes that alone is enough to keep a stable temp in your tank, especially in the summer.

So to Recap, I say one heater is plenty, 150W is plenty, cool your fish down to 74-76 degrees, and enjoy your cichlids!

Cichlid Power!
Pam
Cichlid Power!
Pam

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