I agree with this, I'm sorry
They're popular because like the look of the design, but they're really designed to appeal to people, not to be good for fish. Once you understand more about what fish appreciate - namely, horizontal swimming space - you start see why the rectangular tank has been a staple in the hobby for so long. Oddly shaped fish tanks, ones that are very tall and narrow, tall hexagons, spheres, column tanks - they're not good for fish, and really limit what you can possibly keep in them. The lack of surface area for oxygen change, ability to plant, lack of footprint for bottom dwellers too, difficulty in cleaning and maintenance, all of these things make it even more unappealing to most serious hobbyists. The volume limits it, but even that volume is more workable when it's in a rectangular shape so fish have more horizontal swimming space and is much easier to maintain. These are really a rip off given how much they limit your options and how expensive they are.
Personally I'd sell this one, and scour gumtree and other online sale places and look for a half decent second hand tank that's 60 litres or more. Would really open up your options. I got two 60 litre tanks that came with heaters, filters and lights for less than £40 each. Neither of mine would be large enough for swordtails which get quite large, but guppies, endlers, bettas, and a whole range of schooling nano fish can work (depending on your water GH etc) in that volume with that footprint, and you can plant too.
If it were me, I'd sel
