Multiple Heater sizing?

[mrramsey]

I haven't found the answer to something that was suggested to me recently. I have a 55g tank currently with a single 200w heater mounted about in the center of the tank. Someone suggested I have 2 heaters to more evenly distribute the heat and eliminate cold spots. Also to have a backup if one fails.

So the question is do I use 2 smaller 100-150 watt heaters or 2x200 watt heaters?

Also since this heater came as a package with the tank what features should I be concerned with when selecting a new one?

[Cliff]

I would offer a differ suggestion. If you have a canister filter, I would suggest a in-line heater. That would give you a very even heat as a properly sized canister filter will handle 4 times the tank volumn each hour.

The below in-line heater is the one that I am using and found it to be amoung the best heaters that I have used

http://www.aquaticcommunity.com/revi...duct=262&cat=6

[mrramsey]

I saw those but had not even given it a thought. I am going to be adding a canister filtration unit soon (haven't decided on a model yet).

Any caveats to using an inline heater? I like the fact that there would be nothing in the tank.

Are the sizing requirements the same as a standard? i.e. replace my current 200 with the same?

[Cliff]

In-line heaters should be sized to match your tank just the same as any other heater.

I like using a in-line heater lot better than having a regular heater inside the tank as these in-line heaters do not have any glass parts (won't break easy), don't have to worry about keeping good water flow around them, don't have to worry about fish getting stuck and burned behind them, and I do not like having to look at a heater in my tanks

There is a added bonus of the brand in the link I provided being about the best heater that I have ever used.

[Rocksor]

Cliff,

Did you have to mount the heater to the top of the stand or at least in a higher position than the outlet tube of your canister?

[dmagerl]

I used two larger heaters once and found it impossible to accurately set the temps on both of them to the same temp. Therefore, one heater did all the work, the other didnt do anything.

The only way to get a second heater to work is if the first heater is unable to maintain the temp all by itself. Then, the tank's temp will keep dropping until the second heater with its lower temp setting turns on. As the temp rises, the second heater turns off, but the first heater is again unable to maintain the temp so it stays on, permanently.

So there are two scenarios.
1. With two larger sized heaters, one heater cycles on/off, the other remains OFF all the time.

2. With 2 smaller heaters, one heater cycles on/off, the other remains ON all the time.

If you're wanting a backup, the failure mode of most heaters is where the thermostat contacts weld themselves together and stays on forever. So, the first scenario doesnt help you. The tank will overheat anyway when the contacts weld. The second scenario is the only one that works out as a backup heater. It also helps if one of the heaters fail open, then you at least have some heat in the tank rather than having it cool all the way to room temp.

So in my opinion, its not worth the hassle. But if I were to do it, I'd go with two smaller heaters.

[Cliff]

I have mine spliced into the return line on my XP2 filter a few inches above the filter. It's not attached to the stand at all

The heater also has a spot on it were you could use a small rope (or something along those lines) to attach it the the inside of the stand if needed

I had tried it just on the return and it's been working fine for a year or two now

I'll post some pics shortly so you can see what I mean

[Cliff]

Below is a pic of how I set-up the 300 watt in-line heater on my set-up



You can't see it from the above pic, but there is a spot on the heater to support it's weight if needed. I could not get a good pic of that on my heater, so I found a pic on the interweb that shows it. It's the loop at the top

[mrramsey]

Thanks for posting that Cliff! I will definitely be adding one of these to my set up.

[Rocksor]

Cliff,

Did you have to use the worm gear hose clamp on the heater because the one on the heater itself wasn't sufficient to hold down the rena tubing? Or is that just more of a precautionary measure?