Simple, air pump higher than the water line. Air pump on GFCI.
GFCI is often not well fitted to protecting against fire. It's main defense is against electrocution.
Time for a regularly scheduled electrical safety PSA...
copy/paste:
When dealing with equipment electrical safety should be thought of. When dealing with heaters this is multiplied as they are like shoving a toaster into your water with a thin protective layer over it that can be compromised.
My standard copy paste for electrical safety concerns and recommendation for a CAFCI and GFCI circuits.
On CAFCI, GFCI, and Surge Protection to protect your house, yourself, and your equipment.
I like redundancy and as much protection against equipment failures as possible. Things like Heaters and power strips in our hobby have created more havoc then necessary with the occasional fun dip of lights into the tank...
I would also suggest a CAFCI along with GFCI
CAFCI will help protect your house from fire
GFCI will help protect you from electrocution
And a good surge protector will help protect your equipment.
Individual one shown above. Tripplite makes some good ones. Be warned some newer surge protection devices will stop power from flowing all together once it can no longer provide surge protection. This is actually a good thing IMO for many things like computers/tv/etc but NOT a good thing, again IMO, for many other things like refrigerators, freezers, our aquariums, etc. Some will make an audible alarm when exhausted which is nice too.
Plus a whole home. None last forever and will need replaced eventually based on how many surges and intensity of surges they've been hit by. Surges can come from outside your home, not just lightening strikes, and from inside the home.
Eaton Ultra and SquareD hepd80 are a couple good whole home surge protectors.
Plus having more then one circuit with life support spread across them. I have two additional circuits then what's pictured above to my main tank on the first floor with GFCI at the receptacles so its easier to reset them if tripped. Then the two shown in the picture above go to my basement sump with the GFCI at the breaker. Along with being a CAFCI. There are also AFCI breakers but don't protect against as many arc faults as a CAFCI.
And don't get confused by combination AFCI (CAFCI). That doesn't mean it combines GFCI with it. The packaging has to specify GFCI as well to support both CAFCI and GFCI. Sometimes called dual.
Here's some visuals
And CAFCI protects against both of these where AFCI only parallel
In the US the NEC will typically require a class A GFCI protection in places like a bathroom (fishtank) which trips at 6mA. Some places like commercial applications can use class C, D, or E that trip at 20mA.
http://m.csemag.com/index.php?id=9575&tx_ttnews[tt_news]=102229&cHash=89c8746cdc4a7fd8a3cb93f1d51ba57a
So, to sum it up
I highly recommend at minimum two ways to control and more importantly stop the heater from running.
I highly recommend at least two heaters which means double the ways to control the heaters.
I highly recommend each heater on a completely separate electrical circuit
I highly recommend each circuit to be both CAFCI and GFCI and the use of a good surge protector
I recommend each circuit to be dedicated to the tank.
One other thing I'd like to add to the discussion of safety with electricity and having had heaters cause fires or lots of smoke before
I have smoke/fire detectors in every room but also extra ones where there's lots of equipment like my workbench area, above my electric panel annd especially under the tank stand and sump room.
Under tank stand
Above where all my equipment is plugged into and there's another above the sump where the equipment is at.
Paranoid? Maybe. Quick easy safety features? Yep.
https://www.google.com/search?q=aqu...x0PLSAhWI8YMKHWi-AQMQ_AUICSgD&biw=360&bih=560
