The Nano Sky aquarium from Aquatop is a unique little fish tank. It comes in 4 gallon and 7 gallon sizes. I have the seven gallon in my kitchen, and it brings the room to life. I'm one of those people who name their fish and am totally in love with all of them, so I am careful about where I house them. The Nano Sky gives them adequate space to swim, while at the same time being a tank that's perfect for a small space. 

The front profile of the Aquatop Nano Sky is that of a larger tank, but the slim profile tells a different tale. This could easily be a desk-top tank or a tank to brighten up a corner nook. It's stylish, but it's not a "toy" tank whatsoever. Even the experienced aquarium keeper will be happy with this little gem. 

The light is a super bright white LED unit with 50 LEDs. It easily hooks onto the side of the tank. The light, in combination with the high clarity glass, brings the whole thing to life. I have tetras in my tank, and they glow under this light. 

The filter is a Aquatop 3D-HOB Hang-On Back Power Filter rated for 66 gallons per hour -- that's a lot for a small tank. I'm a sucker for good filtration, so I was glad that the tank came with this unit. The filter also has a very slim profile, so if you want to place this tank against a wall, you won't lose the concept of the tank, one that can fit just about anywhere. The filter is interesting in that the water is pushed into the middle of the filter medium -- called "zero bypass" filtration. You can also purchase this filter separately for any other fish tank that you have. 

As with any small fish tank, you have to be a bit versed on fish keeping, or willing to learn. There's not a lot of margin for error in small tanks, but if you're just going to keep some plants and a beta, this tank is perfect for that. Start with just a few fish and work your way up. 

All in all, this is a nifty little tank, and I can imagine some advanced aquarium keepers getting creative with it with planted tanks, perhaps even with live rock. The lighting is certainly adequate for both. Fins up for the Nano Sky! 

I found the Aquatop Nano Sky for sale in two places: Columbia Water Gardens and TruAqua.

From Aquatop's Website: 

AQUATOP Nano Sky Glass Aquarium Fish Tanks

Available in 4 and 7 gallon sizes, the AQUATOP Nano Sky Aquarium Series is a space-saving and stylish aquarium system perfect for aquarists of all levels. Each aquarium in the Nano Sky Series is built with High Clarity Glass offering a crystal clear view of your aquatic inhabitants with no loss of color. In addition, the energy efficient LED lighting enhances your viewing experience by providing the shimmer of natural sunlight. The included 3D-HOB filter provides superior filtration with a pre-filter and Zero Bypass system that filters every drop of water so your aquarium water stays crystal clear. With proper setup and care, the Nano Sky Aquarium Series offers a safe and healthy environment for your aquatic creatures to thrive.

Features

• High Clarity Glass Aquarium

• 91% light-through rate vs. 84% regular glass

• Polished Edges

• Includes 3D-HOB for superior filtration

• Zero Bypass System

• Energy Efficient Lighting

• Easy to Install and Set-Up

I am not ashamed to admit that I’m a filtration junkie. Hi, I’m Nikki, and I’m an over-filterer. I’ve got a few pico tanks, and I’ve had great success running the API® nexx® 55 FILTER on a nine gallon tank. That’s right. Nine. Why? I’ve got goldfish in it, and they’re filthy fish – delightful, playful, and friendly – but filthy.

I’ve had my share of canister filters in my twenty-plus years as an aquarist. The nexx filter is as innovative as I’ve seen. First, it’s self-priming, which is critical. I’ve never had an issue with priming. Easy.

The nexx filter is rated for 55 gallons (110 with the extension, but I’ll get to that later), but the flow isn’t excessive, making it appropriate for a smaller tank, should you go that route. 

By far the niftiest thing about the nexx is that you can change filter media and clean the filter without turning it off, without interrupting water flow, and without the typical muss and fuss of other canister filters.

How does nexx do this? With a truly ingenious design. The base routes water through the canister, but when you want to change the filter media, simply twist the yellow handle on top of the canister and pull lightly to break the suction between the canister and base. The water flow now routes through the base until you place the canister back onto it.

You can now ferry the canister to the kitchen, or wherever you’d like to clean it. A quick twist of the blue tops opens the two segments of the canister, allowing you to change out the media, which can include any number of proprietary filter media made by API. 

The one drawback, if you can call it that, is that the filter is not as customizable as other canister filters – you are pretty much limited to the media made for the nexx, but that’s a small inconvenience, considering that API’s filter media products for the nexx are various and pretty great, but you’re most likely going to have to find them online, unless you live near an esoterically stocked fish store. They’ve got it all covered with NITRA-ZORB®, BIO-CHEM ZORB®, and PHOS-ZORB®, plus the BioChem Stars. Because I'm using this with goldfish, I use both the NITRA-ZORB and the BIO-CHEM ZORB at the same time, usually buying them in packs of four. 

The nexx is very quiet, which is what you want in any kind of filter. It’s also so easy, that I don’t mind doing media changes (which can be a dreaded task).

There’s an extension that doubles the filter water flow rating and amount of filter. I haven’t used it, and I wonder if the water flow will be the same. Definitely curious about this.

Fins up for the nexx API filter! It’s easy, easy, easy. Did I mention easy? Twist, change media, put back on base, twist again. You don’t have to fill it with water, because it’s self-priming and will suck the water from the tank, which means you’ll have to top off your tank a bit. So far, no leaks, but I’m very careful with my aquatic equipment.

Finally, the nexx has a very competitive price. It's a very unconventional filter, but that's what I like about it. I would absolutely use this filter on other tanks, and plan on doing so.

UPDATE: Lately I've been noticing that the base unit is leaking a bit when I remove the filter unit. I put a towel underneath it to deal with this, and it's fine. It doesn't leak at all when the filter unit is secured to the base. I still very much like this filter and would purchase another for the ease of use and the self priming feature. 

From the API Website:

API nexx® filters are designed to make fish owners’ life easier. Thanks to its unique features, filtration media replacement can be done in only 4 minutes, with no mess from water dripping on the floor.

Beyond aquarium hobbyists, API nexx® filters are also highly appreciated by turtle tank owners because of its independent pump.

The exclusive research grade resin-carbon blend in the BIO-CHEM ZORB cartridge removes compounds that carbon alone cannot remove, providing clean and crystal clear water like no other filter. 

EASY STEPS FOR MEDIA CHANGES

• No need to disconnect hoses or turn the filter off in order to perform filter maintenance
• Safe & easy transportation with the ergonomic handle and tightly sealed lids. Even when filled with water the filter can be carried to the sink with no spillage
• Auto-sliding filtration dose for more hygienic operation – no need to touch a dirty cartridge

SELF-PRIMING, NO DISCONNECT 

The independent and submerged pump pushes water towards the filter instead of pulling it. As a result: 

• nexx® filter is automatically and continuously supplied with water: no priming required, no re-priming needed.
• nexx® filter is ideal for turtle tanks as it can be positioned either above, below or at the same level as the tank. 
• It prevents from vibrations and makes nexx® the most silent external filter
• Filtration never stops, even when removing one of the 2 filtration modules

MODULAR SYSTEM FOR INCREASED FILTRATION

For maximum filtration flexibility, extension can be added to the nexx® filters. Adding one extension will provide additional 55 U.S gallons aquarium capacity and 2 more compartments available for filtration media.

Extensions provide flexibility to move to a bigger aquarium without changing the filtration system, to get more fish, and to use more types of media. When connecting the extension to the filter, the water flow will automatically increase. 

FEATURES

• Aquarium volume : up to 55 U.S GAL (+ 55 U.S GAL per added extension)
• Filter flow-rate : 132 GPH (up to 166 GPH when adding two extensions)
• Pump flow-rate : 260 GPH
• 2 filtration baskets (+ 2 additional baskets per added extension)
• Filtration volume : 0.9 U.S GAL
• Power : 11W

FILTRATION MEDIA INCLUDED

• 2 filtration cartridges API® BIO-CHEM ZORB Size 4. The exclusive research grade resin-carbon blend in BIO-CHEM ZORB cartridge removes compounds that carbon alone cannot remove. Removes organic aquarium pollutant, including: colors, odors, heavy metals and toxic gases.
• 4-side double layered pad for efficient mechanical filtration. 
• 10 API® BIO-CHEM STARS for premium biological filtration
• Can also be used with universal media such as API® size 6 pouches. 
• API nexx® filters are available in 2 sizes: 55 and 110 US gallons. Each filter comes totally equipped with the pump, hoses and filtration media. 
• Extensions can be purchased separately and added on afterwards.