Two Cobalt Neotherm 100W not enough, thoughts?

[joec]

I had purchased two new Cobalt Neotherm 100W heaters several months ago, cheap, $32 each. I thought I was going to set up 40 breeder with 15G sump, but ended up going with Marinelane 53G with 29 G sump, total water volume after rock/sand displacement, probably 60 gallons total.

The two Neotherm 100's will not get temp higher than 75-76 degrees with verified thermometer. My choices are:

1) add another 75W Neotherm which Cobalt Aquatics says should be plenty, for $39. (I do have room to plug it in)?
2) buy two Eheim 150's, Inkbird controller, for for $80, maybe sell essentially new Neotherms, if I can?

I'm not so much concerned about the money, just what is most practical and less potentially problematic?

No animals in tank yet

 

[THX1138CY]

IIRC the rule of thumb is x2 the total water volume = ##watts of heater

 

[redfishbluefish]

You've raise a conundrum that's been bothering me forever.....from manufacturer to manufacturer, watts don't equal watts. You would think that you could simply use a watts per gallon calculation to figure out any manufacturer's heater and simply purchase that wattage.....NOT!

Here's an example of Eheim versus Cobalt. As an example (worse case) look at 300W heaters....Eheim's works for 159-264 gallons, while Cobalt is for only 75 gallons??? As Ricky would say on I Love Lucy, "Someone needs to 'splain that to me." I'm confused!

EHEIM

COBALT:

I'm an Eheim user, and two 100W Eheim Jagers would be more than enough for your total gallons.

 

[joec]

You've raise a conundrum that's been bothering me forever.....from manufacturer to manufacturer, watts don't equal watts. You would think that you could simply use a watts per gallon calculation to figure out any manufacturer's heater and simply purchase that wattage.....NOT!

Here's an example of Eheim versus Cobalt. As an example (worse case) look at 300W heaters....Eheim's works for 159-264 gallons, while Cobalt is for only 75 gallons??? As Ricky would say on I Love Lucy, "Someone needs to 'splain that to me." I'm confused!

EHEIM

COBALT:

I'm an Eheim user, and two 100W Eheim Jagers would be more than enough for your total gallons.

I thought I would have plenty with the two Neotherms, but I appear to right on the crappy side of the threshold.

If I were to add a 75W Neotherm, I would think that three heaters would have sufficient redundancy vs Inkbird? The Neotherms supposedly will not get stuck in the ON position like the Eheims can, which I think is the main reason for a separate Inkbird controller, although I could be wrong?

 

[THX1138CY]

Well I think the issue is Efficiency vs Power Consumption, not all heaters are created equal.