Heater Size

[zak.payne]

I am researching getting back into the saltwater hobby, but this time with a smaller tank. I intend on doing a IM Fusion 20, so I'm wondering what size heater I'll need? I was thinking 100 watt, but during the day while I'm at work and at night, I keep my house at 62 degrees. When occupied it's at 72. I understand it's kind of chilly, but would the 100 watt be wise to keep those temps consistent?

[xthunt]

16 degree raise to 78 degrees from 62, Id start with at least a 150w. 

[Firefish15]

Hey, welcome back to the hobby!

Yeah, I would go ahead and get at least a 100W. One consideration though is that it may be a little larger, so make sure whatever one you'll get will fit where you want it. One brand of heater that's done quite well for me is the Cobalt NeoTherm. On Amazon right now, the 100W  model is actually a little cheaper than the 75W. 

[hotdrop]

The recommendation is 2 smaller heaters so 2 75s might work best for redundancy. 

[paulsz]

36 minutes ago, xthunt said:

16 degree raise to 78 degrees from 62, Id start with at least a 150w. 

I second that. I have a 45 gallons of water in my tank and my basement is something like 65 at night. I needed a 250W to get it up to 78. Originally bought a 150W and it wouldn't get the temp up past 74 or so.