How heater wattage calculated?

[Notsolostfish]

I have the innovative marine 500w. And i was wondering how do you calculate the wattage on a heater? Is it 500w everytime it turns on?

 

[RocketEngineer]

Yes. But that’s also why it needs a controller. The controller turns it off once the set temperature is achieved so it doesn’t overheat the water.

 

[Notsolostfish]

Yes. But that’s also why it needs a controller. The controller turns it off once the set temperature is achieved so it doesn’t overheat the water.

So i have a 20 amp outlet for my saltwater tank which is 200 gallons totsl volume. I am going to be running 2mp40s (76watts) total 1 vectra s2 (72w) for my Uv sterilizer (57w). And return pump vectra m2 (96w) innovative marine 500w (4.17amp) xr30 radions xr30 2 of them (415w) assuming they run at absolute peak. The total is 1216 watts. Meaning i have a 20 amp breaker 2400watts. So i should be good im assuming? Depends on how cold it gets in my basement in winter i might add another 500 watts

 

[jda]

Your math checks out. However, you really need 2 circuits. Put your return pump on one and your flow pumps on another. Split up your other equipment.

You never want one tripped breaker to crash your tank.

Get a Ranco, or something, to control that heater(s). Ranco is not expensive and is industrial grade that you will likely have for the rest of your reefing life. Some folks like Inkbirds, but they have varying degrees of reliability and failure rate - the probes are not always good. Apex can be OK, but the probes can drift too. You also want dual control on your heater so that both the Ranco/Whatever and the internal heater thermostat have to fail before your tank overheats.

Depending on where you live a single 500w heater might not be enough. I am in Colorado where the low humidity does a lot of evaporative cooling - it takes about 1800w of heaters to keep my tank rock solid. 1200 would probably be OK, but they would run more. If you live in south Florida, then 200w might be enough.

 

[Notsolostfish]

Your math checks out. However, you really need 2 circuits. Put your return pump on one and your flow pumps on another. Split up your other equipment.

You never want one tripped breaker to crash your tank.

Get a Ranco, or something, to control that heater(s). Ranco is not expensive and is industrial grade that you will likely have for the rest of your reefing life. Some folks like Inkbirds, but they have varying degrees of reliability and failure rate - the probes are not always good. Apex can be OK, but the probes can drift too. You also want dual control on your heater so that both the Ranco/Whatever and the internal heater thermostat have to fail before your tank overheats.

Depending on where you live a single 500w heater might not be enough. I am in Colorado where the low humidity does a lot of evaporative cooling - it takes about 1800w of heaters to keep my tank rock solid. 1200 would probably be OK, but they would run more. If you live in south Florida, then 200w might be enough.

I do have a 20 amp circuit just right next to it for my freshwater tank. And i did my calculations on that tank. And its running 1015watts. Which is literally nothing. I can probably plug my UV, and my 2 radions + my roller matt. And be good

 

[jda]

That won't likely matter if a breaker trips. Split up the return pump from the flow pumps. If one circuit goes out, then you still have moving water and oxygenation. You should do the same with the FW tank too, IMO.

 

[RocketEngineer]

Not all of us have that option. In my case, the tank is the complete opposite corner of my house from the breakers and I have no access without opening walls. I understand that two circuits are best practice but reality dictates otherwise.

 

[mike550]

@charbel101 I’d feel comfortable with one 20A circuit because the likelihood of having everything pull max load at the same time is pretty low. FWIW when I power up equipment I don’t turn everything on at once to reduce the risk of a startup surge that trips a breaker. If you have or are planning to get an Apex controller it will provide you with Voltage, Amperage, and Power (as Watts) for the outlets.

 

[thedon986]

I have the 500w IM HELIO as well and it pulls 350w when on according to my Apex. I saw another post on here about how it pulls less than what IM says.