oh geez honestly luckily isnt a house spider instead it would bring a new ballpark of scaries into the aquarium also a water bottle is alot different than saltwater i can imagine the spider would be screaming if it stuck into ocean water although i have seen some make airbubbles underneath there abdomen i guess like jurrassic park “life will always find a way”Just tossing it out there. The neighbor kid stuck a black widow spider in a water bottle, filled it up to the top and closed the lid. He left it outside for about two weeks in the sun. I opened the bottle and the spider came crawling out.. just FYI.
But chances are if it was a house spider it would have eventually made its way out of the tank if it could.