I'm new to aquariums (and don't yet have one, I'm trying to gather as much information as I can before taking the plunge).
I've space for a tank up to about 30 UK gallons/130L (really no larger than 28"x18"18" or so). I might be able to go bigger, but not much more.
I'd cycle it without fish before stocking it, and reading around on the various care sheets and on other forums I've narrowed it down to a couple of options to explore (i.e. "rule out completely") first- chosen on the basis that they seemed reasonably easy and interesting- the Weather Loaches or Blind Cave Tetras. They wouldn't be sharing the tank with any other species.
I've several questions-
I'm finding conflicting information on water volumes- the caresheet here says 300L (66 gal) for the minimum tank size, whereas others suggest between 10 and 80L 30+ seems to be commonly quoted). I understand they can get quite large and should be kept in a group (I was thinking I'd be able to keep 3), but which do I believe?
Being a bottom living fish, will a 24"x18" footprint be large enough? Or is this why some of the suggested tank sizes are so large?
With the tetras, I've seen it suggested that they'll be OK without heating- but is that going to be true in a UK winter? (The house gets quite cold at times- especially at night- certainly less than 16 degrees C).
Given how hard the water in London is are either species going to have a hard time with the water chemistry?
If you have any other advice and experience I'd be pleased to hear it. Thanks in advance. :)