Heater Sizing.

[GGobblin]

Have a Finnex 300w Deluxe Titanium heater with 810 Finnex controller on my 75gal glass tank, maintaining 78 degrees like a champ.

I'm moving up to an Acrylic 240gal 96x24x24 and was wondering if I can just add another, so 600w total.

I know acrylic retains heat better and I like to keep the wattage down incase one gets stuck on. A 300w stuck heater won't be enough to cook my fish.

Question is, will 600w be enough given the difference in tank size and more efficient materials ?

 

 

 

 

 

 

 

 

[Ken Burke]

Recommend using an ink bird controller. They have models that can control two heaters, and provide a layered approach for controlling water temp.  
 

you set the heater temp just over the desired temperature, and the ink bird at temp.  This result in the system needing 2 failures to get runaway temps.  I’ve attached and example of what I’m talking about.

[Guppysnail]

I do not have acrylic tanks and have never had a tank as large as you are going. I do use dual heaters in all tanks 20g plus. I find I can go with much less wattage and it maintains temps much more consistently and they “seem” to turn on less (I’ve never actually timed or anything I just noticed a few times I seem to not see the light as often). 

[Fish Folk]

On 2/8/2022 at 11:18 PM, Ken Burke said:

Recommend using an ink bird controller. They have models that can control two heaters, and provide a layered approach for controlling water temp.  
 

you set the heater temp just over the desired temperature, and the ink bird at temp.  This result in the system needing 2 failures to get runaway temps.  I’ve attached and example of what I’m talking about.

I’ve got an inkbird controller, but have had a hard time properly setting it up. It beeps randomly… seems to have a mind of its own. I eventually disconnected it and am waiting a slow Saturday to properly learn it. If you go this route, just make sure you have time to really dial in the instructions. 

[jwcarlson]

On 2/8/2022 at 10:18 PM, Ken Burke said:

Recommend using an ink bird controller. They have models that can control two heaters, and provide a layered approach for controlling water temp.  
 

you set the heater temp just over the desired temperature, and the ink bird at temp.  This result in the system needing 2 failures to get runaway temps.  I’ve attached and example of what I’m talking about.

 

I'll second this suggestion.  I've only had this Inkbird controller for about a month on my 75 (with two 300W heaters keeping it at 85).  But I use a lot of Inkbird controllers for honey bee queen cell incubators, chicken egg incubators, and egg hatching chambers over the years and they're just absolutely awesome.  Like Ken says, you'd need two failures to cook fish and any single failure to heat would theoretically be a lot less catastrophic as you're more likely to notice and be able to fix the problem.  Basically coming home to lethargic fish vs coming home to nearly boiled ones.

[Beardedbillygoat1975]

I think you’ll be good with 600w if goal is same temp of 78.
 

The ink bird is a good call just make sure to buy the right one. I have one now that was the wrong model. The Amazon listings were confusing as I even followed the recommendation from this site but they sent a different one. I’m keeping this one to keep my fish room cool this summer and eventually I’ll buy the right one!

[GGobblin]

Yeah, I can even build my own controller. I will be using 2 heaters, just not sure if 2x 300w heaters will maintain 78 in a 96x24x24. Room temp is 70