Ultum Nature Systems UNS 5N Ultra Clear Rimless Nano Aquarium 5 Gallon Review (2026)

Who this tank is for

The UNS 5N is aimed at aquascapers who want to move up from a very small nano tank into something with enough depth to plant a proper foreground carpet plus taller background stems, while still keeping the footprint small enough for a desk or shelf. Ultum Nature Systems built its reputation on rimless glass made specifically for display quality aquascaping, so this tank suits someone who plans to compete, photograph, or simply take real pride in the finished layout rather than treat the tank as a basic holding container. It is sold in the 5 gallon size class, with a listed volume of 4.6 gallons, or 17.4 liters, which gives a small school of nano fish or a shrimp colony a bit more stability than the smallest nano sizes offer. It is not built for anyone wanting a large centerpiece fish or a heavily stocked community tank.

Specs and design in plain terms

The UNS 5N measures 14.17 by 8.66 by 8.66 inches, or 36 by 22 by 22 centimeters, using 5mm thick glass described by the maker as 91 percent clarity low iron Diamant glass, which keeps the greenish cast of ordinary glass to a minimum. The panels meet at 45 degree precision mitered joints bonded with German silicone, a technique Ultum Nature Systems says roughly doubles the bonding surface area compared with a simple butt joint, adding structural strength while keeping the seams close to invisible. Each tank carries a laser etched UNS logo in one corner rather than a printed sticker, so the branding will not peel or fade over time. A custom cut black foam leveling mat ships with the tank to sit underneath it and absorb minor unevenness in the stand surface.

Setting it up and living with it

Setup starts with the included foam leveling mat, which should go under the tank on a flat, sturdy surface before anything else, since rimless glass depends on even support along the base. From there the extra depth compared with the smallest nano tanks gives real working room to layer hardscape, wood and stone toward the back while leaving open swimming space and a planting area up front. Because it ships as bare glass, a nano light, small filter and lid all need to be chosen separately based on the footprint and desired plant growth. Ultum Nature Systems backs the tank with replacement shipping at no cost if it arrives damaged, provided you document the damage with photos and file a claim with the carrier, which is worth doing immediately on delivery.

Trade-offs and how it compares

The main trade-off is that the UNS 5N is glass and a leveling mat only, so the total cost of a finished setup climbs once you add a light, filter and lid, and Ultum Nature Systems equipment tends to sit at the premium end of the nano tank market. Reaching every corner of the longer footprint with even light also takes a nano fixture with reasonable spread rather than a narrow spotlight style light. Against the LANDEN 36N, which ranks just ahead of it in this size class, the two are close in build quality and glass clarity, while the UNS 5N distinguishes itself with the laser etched branding and documented mitered joint technique. Compared with simpler 3 gallon nano kits, the extra depth here noticeably widens what is possible for a planted layout.

Verdict and who should look elsewhere

With our score of 8.6 out of 10, the UNS 5N is a strong choice for a nano aquascaper who wants genuine display quality glass and is prepared to source a light, filter and lid to match. The mitered seams and low iron clarity make it a tank worth building a real layout around rather than a throwaway starter container. Beginners who want a complete kit with a light and filter already included, or anyone working with a very tight budget, will likely be better served by an all in one nano aquarium kit instead, since this listing covers the glass and leveling mat only.

Frequently asked questions