Since you're reading this review, I guess you've already liked Umbra's FishHotel enough to care. As a pet lover like you, I urge to be open-minded to my points and read on.
I have been a proud owner of 6 betta fish for a year now, and between the 6 of them, my fish have given me many challenges, e.g. rotting tail, tailing biting, etc., that may qualify me as Umbra's FishHotel aquarium reviewer more than other reviewers here. Thus, I recommend that you stay away from this product.
As a betta beginner, I used to house my fish in this aquarium. It was all fine and dandy for the first month. Then, my bettas started bitting their tails, got their tails infected, and just stayed in one place, not swimming around happily like they used to. Worried, I researched and tried everything to fix the problems, from changing the water more often to give them live food. Nothing worked until I put each of them in a 2.5-gallon tank with heater and slow filter. The 2.5-gallon was big enough to put more plants and a couple of wooden logs for hiding places for my bettas. Now they are truly happy and I hardly have to do anything except for feeding them.
The lesson that I learned was that this aquarium is just TOO SMALL for a betta.
Amazon's dimension for the white case is accurate that it's a 7.5" wide x 7.5" deep x 8" high, but notice that the glass bowl is 1" shorter, which barely gives a betta a gallon of water to live in. Since it's too small, your betta will only survive in it and develop bad habits and will not thrive in his environment. Kinda like you and me, we can survive living in a small room if we're fed properly, but we won't thrive and live to our maximum longevity without enough room for exercise and entertainment.
Yes, entertainment/discovery. Experienced betta owners will tell you that bettas do get bored, and that is one of the main reasons they'll start biting their tails and once they do, they tend not to stop. Imagine, your fish looking raggedy like a used cloth, and the reason you bought him in the first place was his beautiful long plumage. How do I know this? Many pet owners will agree with me that your loving pets will tell you what they need. And, you just know if you care about them in return. Big aquariums have enough room for your fish to swim around for exercise and discovery.
The belief that bettas prefer small environments is false. My bettas swim to every corner of their 2.5 gallons and do what they do because they don't just have a place to live but a whole environment to thrive in. The same principle applies to us, humans. Your pet will live longer with you if he has enough room to swim around for exercise. (Update: My bettas are now in 6-gallon Fluval Edge and 5-gallon Fluval Chi aquariums).
In case you don't know, experts recommend changing water for one-gallon aquariums at least once a week. My suggestion is twice a week for Umbra's because you'll see that by the third day your betta will produce quite an amount of bodily waste that pollutes his water. Living with ammonia build up for more than a week will cause your bettas to develop bad habits or GET SICK. Not to belabor the simile, like you and me, bettas live better in a clean house. So, with Umbra's, you'll have to either get a filter or be CHANGING WATER CONSTANTLY, a huge inconvenience if you have a busy schedule. Large aquariums have enough water to temporarily dilute the toxicity of waste and usually come with filters. The filter keeps the water cleaner longer so you don't have to change the water as often.
Small aquariums like Umbra's will also experience FLUCTUATING WATER TEMPERATURES (if no heater) and your betta will just sit around looking lifeless because he's cold. If you install a heater with Umbra's FishHotel, let me ask you: will your chic aquarium still look chic with a long black electrical cord jutting out from the bowl and into the electrical sockets? Plus, since most betta's aquarium heaters do not have button/setting for adjustments, small bowls like Umbra's don't have enough water to offset the heat. You might end up overheating your poor betta.
If you like attractive well-designed aquariums, I'd suggest Fluval Chi Aquarium Kit, 5-Gallon or Fluval Edge 12-Gallon Aquarium with 42-LED Light, Black Since you're gonna pay premium for aquariums anyway, you might as well make a better-valued investment. These not only look stunning, they come with a powerful filter, LED lights, the whole package for you to properly care for your betta. Another pro about these is you could add other fish as neighbors/tankmates for your betta. More importantly, these are real aquariums, not bowls which Umbra's FishHotels are. Bowls are for soups, not pets.
Another reason NOT TO BUY this is even though the design looks cool, you won't see your betta very well with those covered areas that supposedly should act as "hiding places" for your betta. They'll significantly BLOCK YOUR VIEW of your pet, decorations, and everything in the tank. WHAT ABOUT DECORATIONS? If you like to decorate your tank, making a little zen heaven for both your fish and your room, Umbra is too small to do so. At most, you can put in gravel and a couple of silk/plastic plants (live plants will probably be too big and sensitive to live in bowls like Umbra's); otherwise, your pet can't swim around.
Lastly, how about that this aquarium is way OVERPRICED? Why didn't they have the bowl made out of acrylic and reduce the price in half?
If after reading my review you still want to purchase it, please do and check it out for yourself. I just hate to see you buying an overpriced product and will discard it when you see your pet suffering.
Hope this helps.