Way back in my early fishkeeping days, I didn't have a gravel vac (because mommy and daddy wouldn't buy me one...) I used to put my hand in and stir up the gravel really well, then use a cup to scoop out the water while the poo and junk was floating around. If it would start to settle, i'd stir it up again and keep scooping.
Maybe they just dumped the whole tank out? I would assume that they kept local fish mostly because of the difficulty of transportation. They could easily get water of the exact ph from a lake or stream.
Take a look at some of the older aquariums. They used to have a slate bottom. I also ran across a few with some really nice metallwork in place of the "fake wood trim" may have today.
OK, here's the answer from the old people. I didn't have fish back then but lots of school class rooms did. We used to have fish tanks with a few gold fish, tadpoles, little turtles, maybe other things. The tanks were about 2'x1'x1' or so. They would put the fish into a small container and dump (or dip out) all the water. I remember rinsing the gravel if there was any and spreading it back out. I don't remember what happened to the plants. Anyway, after putting in fresh water, we put the live critters back in. The gravel was usually bright colors. I don't remember having any heaters, filters, or other stuff.
Well my mom told me when she had fish that she had to drain the tank and risne that gravel and she could not keep fish alive, probably because there was no bacteria to break down ammonia and nitrite.
I have an aquarium book from 1968. The book is called How to Have a Successful Aquarium by Norman G. Hovlid, Discoverer of Biological Filtration for Aquariums. It too refers to the use of a dip tube, as RTR's article above does. Another name for it was "sediment remover". You put your finger over the end of the tube and place the tube over the sediment. When you lift your finger off the end at the top of the tube, it draws the waste off the sediment through the bottom of the tube. You immediately put your finger over the top of the tube again and empty it in a receptacle, such as a bucket.
The book also states that the better tubes were designed with a trap in the middle so that you could make several dips before having to empty the tube. Wonder why it took so long for someone to think of putting a hose on the end of the tube? :thud:
Also of interest in my book is a short advertisement about the Miracle (undergravel biological water conditioner) filter. Apparently, the concept was new or relatively new at the time. The discussion gives the benefits about the way in which all of the water is circulated and waste and other organic matter is drawn into the sand and converted to chemical compounds, "thus stimulating plant growth." It goes on to talk about the gases given off by the bacterial conversion, etc. and that "You need never clean the aquarium until you wish to replant it."