Heater redundancy, which wattage do i need?

[PegasisR]

I want to run two heaters at half power wattage for a 139g. My goal for this is so if one screws up it wont overheat my system being that it cant heat the tank up individually but can together. What would be the wattage i need to achieve such goal? Or would it be better to have both that can individually heat up the tank?

Looking at the neotherms
and finnex hma-s!

Thank you

 

[EmdeReef]

I want to run two heaters at half power wattage for a 139g. My goal for this is so if one screws up it wont overheat my system being that it cant heat the tank up individually but can together. What would be the wattage i need to achieve such goal? Or would it be better to have both that can individually heat up the tank?

Looking at the neotherms
and finnex hma-s!

Thank you

You should get a temp controller. Inkbird makes cheap reliable ones. I would never rely on the built thermostat alone.

The problems usually don’t come from the heater dying. The real risk is the thermostat getting messed up and you end up with a cooked tank.

 

[madweazl]

Heaters in the 150-200w range should work well.

 

[lapin]

Heaters are not the only source of tank heat. Pumps and UV units can produce heat. Also the room temp of your house and the room the tank is in can make a difference. I would do 2 that can handle a 150 gallon tank ea. They are always overrated to look good.

 

[madweazl]

Heaters are not the only source of tank heat. Pumps and UV units can produce heat. Also the room temp of your house and the room the tank is in can make a difference. I would do 2 that can handle a 150 gallon tank ea. They are always overrated to look good.

I don't agree with this statement and it totally defeats the purpose of what the OP intends to do.

 

[lapin]

To justify my statement I found that a 150w heater rated for tanks up to 75 gallons was on 24/7 to keep my 75 gallon at 74F. If I had 2ea 75w heaters I do not think it would be enough. Now I could be wrong.

 

[madweazl]

To justify my statement I found that a 150w heater rated for tanks up to 75 gallons was on 24/7 to keep my 75 gallon at 74F. If I had 2ea 75w heaters I do not think it would be enough. Now I could be wrong.

What brand heater? A single 150w Visi-therm can maintain my tank down to 15° below normal tank temps without issue.

 

[ihavecrabs]

My recommendation is buying two heaters that are slightly undersized. This is important because if they get stuck in the on position, you'll not want it to over heat the tank.

In addition to that safety, you want them to be slightly undersized so that if one dies in the off position, you don't want your tank to get too cold.

And in addition to the above.... get a heater controller that monitors the temperatures and turns the power to the heaters off if the temp goes out of the range you select.

 

[lapin]

What brand heater? A single 150w Visi-therm can maintain my tank down to 15° below normal tank temps without issue.

These were glass heaters you get at the Petco. I dont recall the brand. I lived in San Francisco and my tank was in my garage. Not too much colder than my house. I now have a large tank and proper heaters with controllers. All controlled by an Apex for safety reasons.

 

[ihavecrabs]

My recommendation is buying two heaters that are slightly undersized. This is important because if they get stuck in the on position, you'll not want it to over heat the tank.

In addition to that safety, you want them to be slightly undersized so that if one dies in the off position, you don't want your tank to get too cold.

And in addition to the above.... get a heater controller that monitors the temperatures and turns the power to the heaters off if the temp goes out of the range you select.

Wow, I just checked finnex size recommendation and on tank size for 120g they recommend a 500w heater.

I run two 300w on my 240g in a basement (cooler room)..

That recommendation seems crazy oversized.

I'd recommend two 200w myself for that size tank.

 

[Breadman03]

I have a 150 with a 120 basement sump. I generally have a 100 watt first stage, 250 watt second stage, and 250 watt third stage. Keep in mind that my basement gets pretty cool. During this polar vortex, I swapped the third stage to a 1000 watt because I had it laying around, but a 500 would have been plenty. Keep in mind that my basement doesn't so much have a draft as it has a breeze and will get into the 40's pretty often.

Assuming you have a sump under the tank, I suspect that a pair of 150's would serve you well. Understanding budgets, I would also suggest at some point looking into a controller such as an Apex ($$$, but very useful) or a Ranco ($, but industrial reliability for temp control).

 

[PegasisR]

My recommendation is buying two heaters that are slightly undersized. This is important because if they get stuck in the on position, you'll not want it to over heat the tank.

In addition to that safety, you want them to be slightly undersized so that if one dies in the off position, you don't want your tank to get too cold.

And in addition to the above.... get a heater controller that monitors the temperatures and turns the power to the heaters off if the temp goes out of the range you select.

What wattage for the two would you reccomend for a total 139g system? Also what brand? Thank you!