Did you know they have cloth covered extension cords now in designer colors?Gee, wish I had suggested you MAIL THE THING BACK!!!!
OK, yeah that IS old. Knob and tube hasn't been used for almost 90 years. Your house isn't as old as our current one but it never had k&t, no electricity until the 1950's based on the cloth covered coated wires. Our prior house had some k&t in the attic and walls (but no wire in use, it was replaced with surface mount some time before I bought it in '88), it was built in the early 1920's I think.
I expect you also have a fuse panel so you'll be replacing that with a circuit breaker panel.
Depends on what kind of filter you have! Mine has pads that get rinsed out. I have this filter:
https://www.amazon.com/AquaClear-20-Power-Filter-Listed/dp/B000260FUM
it uses these pads:
https://www.amazon.com/Aquaclear-50-Gallon-Foam-Inserts-3-Pack/dp/B0002AQK4S
I also have one of these for extra bacteria substrate. Since I have this in the filter, I only use 2 of the pads:
https://www.amazon.com/Aqua-Clear-A1372-Aquaclear-50-Gallon/dp/B000A7BCG4
and a bag for charcoal that I can refill. I'm not big into buy and throw away. But I know some filters have media that is not reusable. You might have one of those.
If the gravel is still full of gunk, yeah I would vacuum it again in a few days. Just enough to get the bulk out, don't want to have to add too much more new water so soon if you can help it.
Whoo hoo, I get to "like" it twice since you posted it in 2 threads!
Where are you going to live in a year when she's overgrown the house?