External Heaters

[piper]

Hello all, I have a 66 (US) Gal tank and due to many set backs I'm ready to start cycling it again. I originally bought two 300w Hydor External Heaters to run in parallel. These use 16mm hoses which are the same size as my Ehiem 2026 filter.

But I'm now thinking that 600w of heating might be too much and I should have gone for 2 * 200w Hydors instead, originally decided against this as these used 12mm hoses.

Have a got too much power or can I just set them to lower temps ?

Or should I go for the two smaller heaters and fiddle with the hoses ?

 

[simonbrown403]

If i'm corect a 66gal US is about 280ltr, the rule of thumb is 5wat per gal, so a 300watt on its own is more than suitable.
I keep discus and have had no problems maintaing a constant temp of 29'C in a 66gal UK with one heater 300watt heater, but i use a second one as a back up just in case the first malfunctions, i'd keep it, you should always have a back up handy.

 

[piper]

Yeah I know that a single 300w would be fine but I wanted to run two simultaneously so if one stops working the other will already be there for a back up, like you said. Also running two at say half power would increase their life.

My main worry was that running the two together would mean I would get higher temps, but by the sounds of it this will not be an issue.

Can you confirm that your using 2*300w heaters both on at the same time?

Thanks

 

[rdd1952]

For a tank that size, I think it's best to run dual heaters and filters for better filtration, circulation and heat control. You don't need that much wattage but it probably won't hurt anything. I guess it's the same as being over filtered.

 

[cujoho78]

I agree that 600W is overkill, but they are designed to shut off at the specified temperature that you set them at. So once they get to the right temperature, they should shut off by themselves and thereby not overheat the water. You should be fine with them, and you wouldn't have saved more than a few dollars by buying smaller wattage heaters anyway.

 

[Matty]

straight up, yes.

 

[SamUK]

i have 2 300w heaters in my 75 gallon tank and it keeps the temp perfect.

 

[rdd1952]

i have 2 300w heaters in my 75 gallon tank and it keeps the temp perfect.

I have 2 Hydor inline heaters in my 75 gallon running off Fluval 304s and it's the same. I use a digital thermometer and have moved the probe from one end to the other, within a few inches of the filter ouput. The temp is within .1 degrees from the 2 outputs. The tank temp stays within a .2 or .3 degree range all the time. As someone else mentioned, it may be overkill but it certainly won't hurt. They just won't actually be on and heating very often.

 

[piper]

Thanks for your help people, was just worrying over nothing then

 

[fishing4exotics]

Hi piper, in most of my tank, if at all practical. I use 2 heaters that equal the watts needed to heat a particular tank. If one of the heaters fail to go on the other heater will keep the water at a tolerable temperature for your fish. And If the opposite happens where a heater sticks on. That single heater is not enough to boil your fish. So, in our case I would use 2 150 watt heaters rather than 2 300 watt heaters. Kind of a fail safe redundant system. I do the same with filters for my big tanks. 2 pumps running a sump rather than one single pump. Just a thought

 

[piper]

That’s a very good point fishing4exotics, in future I will do that. I think the Hydor external heaters are meant to have some fail-safe mechanism to stop them over heating like traditional heaters can. So hopefully in this instance having double the power shouldn’t deep-fry my fish even if one goes wrong.

 

[cashton]

Thanks for your help people, was just worrying over nothing then

Well, maybe not. Another reason for using two smaller heaters is not only incase one poops out you still have one keeping the water from getting too cool, but also the thermostat can malfunction and the heater can heat to it fullest capasity. So if you have a smaller heater, it can't heat the water too terribly high and will also do it slow enough that a watchful tank keeper might catch it in time. If you have one huge heater as in your case and this happens.......fish soup.

 

[sub.42]

It's just like a big Northstar V8 engine!

Uses all the cylinders when required, and shuts a bank down when not needed, thus saving fuel.

What I mean is you will have less temperature lag when(if) you chill the tank. My Juwel Rio 180 uses two 200w heaters because I don't have my central heating on at night, and the air temp in the dining room drops to about 14/16 degrees C. So both are on full boot for the early morning, until the ambient temp rises.

One word of warning, I have had a case of overcooking the tank with twin 300w heaters when one stuck on. I can't see you ever over doing it with heating. The higher power heater will merely catch up faster...or cook them quicker if it fails.....its a risk.

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