Heater Size Question

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Aquarium Advice Freak
Mar 22, 2008
South Philly, Pa.
Hello - I have a question regarding heater size. I have decided to purchase a Hydor in-line external heater for my 36gal corner tank. My problem is I REALLY like the cold. In the winter time it is safe to say the room where the tank is (and I sleep) rarely goes past 50 degrees. Except for the weekends my kid is down - then I tolerate 70ish. In the summer my air is running and I try to keep it down to 68 --- The question is do I buy a 200 watt rated for 26-53 gals or do I buy the 300 watt rated for 53-80 gals? I'm worried that the 200 watt may get too much of a workout - Thanks and I very much appreciate your time helping me and my son set up this tank :p
You want 3 watts per gallon heating. I suggest doing it with more then one heater so you will have a back up incase one fails. I have 3 150w heaters on my system. Never depend on one to do the job. If you keep your house cool like that it is a good idea to spread it out over 2 heaters.
Generally a heater will raise the tank temperature about 10 degrees above the ambient room temperature. Manufacturers' specs vary, so you may want to give Hydor a call (there should be an 800 number on their website) and see what they recommend. I agree with Ziggy - I would use two heaters. I would think that one inline 300 watt heater and then one submersible heater from 200-300 watts would be good since your ambient room temperature is chilly.

The "standard" heater size for a 10 gallon tank is 50 watts. I have a 75 watt heater in my 10 gallon because my ambient room temperature is about 68 and I want the tank to be 80 degrees and the temperature difference is more than 10 degrees, so I use a heater with more wattage than the standard recommendation. I probably could have gotten away with the 50 watt heater in this case but the point is to use a heater with a higher wattage and/or use two heaters to get the water temperature that you want, depending on such factors as tank size and room temperature.
You are looking for a 25+ degree differential betwen ambient air and water. I would go with 300w of heating, but I agree on using 2 heaters. I'm not a big fan of inline heaters. What do you if/when it breaks?
To parrot, I'd go with two 150w or a 300w.

The benefits of going with two 150's is that you have diversified your heatfolio, so you don't have your entire tank relying on one heater.

I've heard horror stories of people coming home to nothing but death because (1) heater got stuck in the "on" position and made it too hot, or (2) heater busted and they got too cold.

Having two heaters fixes both of these problems: if it gets too hot and one shuts off, too cold and the other kicks in to help out.
Thank you very, very much -- Two heaters it is -- one inline and one in the tank -- of course this means I will be pawning my stuff and selling my blood at the local hospital to offset the expenses that are racking up with this hobby -- I have to be crazy -- I've had plenty of psychology training to know that this tank is causing me compulsive obsessive disorders ---- AND I DON'T CARE I GOT TO HAVE THIS TANK --- thanks again - you are all really good people at heart to take the time to help out me and my son do this tank right - Peace
Thanks Fishyfanatic - like my wallet really needed to here that - but you are probably most correct - presently I am suffering from CEB (Cronic Equipment Buying) because I only want the best for the tank and F.I.S.H. Syndrome (Fast - Instant - Simultaneous - Hurry Syndrome) because I want this tank running yesterday -- :D
haha, it's an illness really. One is never enough. Soon you will be moving furniture out of the house to accomidate a new tank. We are selling a chair, end table, and ottoman to make room for our 150 gal tank. You do what you have to do to feed the addiction.
I feel like I'm listening to a conversation b/w two drunks at a bar: not healthy, lol.

Warped1, how is the "weekend only" scheme of working on the tank treating you? Didn't you say you're only going to work on it with your son on the weekends? That has got to be killing you.

That inline heater is gonna be neat, i've never had one but they seem super cool. Trust us, it is nice having that extra piece of mind that with two heaters, your heat source is diversified and you'll get the benefits mentioned above should something go wrong.

My MTS syndrom has ceased. I've been fortunate and only ever bought my first (5 gal) fish tank. I inhereited the 55 gal acrylic, w/ a 10 gal sump and my 20 gal Tex Cichlid tank. Though well under teh 1"/gal rule, my Tex Cichlid really needs a bigger tank but I don't have anywhere to put it or any money to buy it.

So yeah, I'm holding steady at 3 tanks now, though my 5 gal is not in use. I think I may get rid of it since it's so old but there is some sentimental value there so I dunno.
I should - next weekend when my son comes down - move all his stuff out of the bedroom and tell him we are getting more tanks and it his his fault for waking up my fish addiction after 28 years --- But then again - knowing my son - he would be game for the idea - Peace
As for the every other weekend thing, It has its good side and bad side. The bad side is --- Heck Yes ! -- I get itchy to start it - But I have found that the best things are worth waiting for -- The good side is that I have extra time to silicone the pieces of driftwood he picked out together. We arranged them a hundred different ways until he picked out the one he liked - and naturally the arrangement he picked out defies the laws of gravity and physics - hence the silicon and waterproof screws - by the time he comes down next weekend the wood will be together and he didn't have to witness me cursing like a trucker or fell sorry for me when I realized I siliconed my pants pocket closed (Please don't ask how)
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