Late to this one, sorry if these are repeats...
You have 220 amps coming in, more than half of which powers your tanks.
You plan your vacation around your "tank-sitter".
You take calls at 10pm, while on your honeymoon, because the tank is "too quiet".
You have a friend who will drive the 60 miles to your house to see why. AND he answers the phone after 10pm on a weeknight.
You watch Blue Planet and go, "oh, yeah, I have those".
Your skin is pickled from all the lime and brine.
You see nothing wrong with using a cereal bowl to plunk pulled algae and slime into before throwing it out.
You have more rocks in your house than in your yard.
You don't need spotlights to circumnavigate your house, from the outside, after dark, as long as it's still viewing time.
People have said either of the following to you:
"This is like SeaWorld" "This is better than SeaWorld"
You get asked about Nemo roughly 40 or 50 times per day.
You're considering changing your last name to Cousteau.
You've named any of your children Pyle, Randall, or McCulloch.
You can't taste salt any longer.
You wonder how big a tank you'll need for that 8' Blacktip that just passed you while diving.
You routinely visit the gadget aisle of your local supermarket to see if there are any neato things you can use for the tank(s).
You know the chemical composition of all aquarium additives, and their civilian (cheaper) equivalents.