How many other members are getting ready to do battle with the near 190 mph Irma?
I'm sure we'll lose power. May lose the whole house...
How long can a pond pump and filter not run and not become toxic?
It's not on a circuit that I normally use with my generator.
It appears, if the prognosticators are correct, that your area will feel the full impact of this most dangerous storm.
As a native Floridian, I have experienced first-hand some of the real nasties: Hurricanes Frederick, Erin, Opal, Ivan, Dennis even parts of Katrina.
Sadly, Backyard ponds do not usually survive these storms intact, They will catch, it seems, every piece of debris that was blowing around, Fish loss will range from major to total (with or without power). With storm surges, entire ponds wash away leaving only a hole in the ground.
Your only concern should be for the safety of yourself and family. If the authorities request that you evacuate, DO SO. Once the storm hits and during its passing and for a period afterwards, you will be isolated with no-one able to get to you and even if they can, the sheer number of people requiring assistance makes assistance available on a first come-first served basis. Communications may be non-existent even cellular.
Find and move to safer shelter, to do otherwise is a gamble that one should never take.
Good luck!